HZB Newsroom

  • BESSY II shows how solid-state batteries degrade
    Science Highlight
    09.07.2024
    BESSY II shows how solid-state batteries degrade
    Solid-state batteries have several advantages: they can store more energy and are safer than batteries with liquid electrolytes. However, they do not last as long and their capacity decreases with each charge cycle. But it doesn't have to stay that way: Researchers are already on the trail of the causes. In the journal ACS Energy Letters, a team from HZB and Justus-Liebig-Universität, Giessen, presents a new method for precisely monitoring electrochemical reactions during the operation of a solid-state battery using photoelectron spectroscopy at BESSY II. The results help to improve battery materials and design.
  • A new way to control the magnetic properties of rare earth elements
    Science Highlight
    17.07.2024
    A new way to control the magnetic properties of rare earth elements
    The special properties of rare earth magnetic materials are due to the electrons in the 4f shell. Until now, the magnetic properties of 4f electrons were considered almost impossible to control. Now, a team from HZB, Freie Universität Berlin and other institutions has shown for the first time that laser pulses can influence 4f electrons- and thus change their magnetic properties. The discovery, which was made through experiments at EuXFEL and FLASH, opens up a new way to data storage with rare earth elements.
  • From waste to value: The right electrolytes can enhance glycerol oxidation
    Science Highlight
    01.07.2024
    From waste to value: The right electrolytes can enhance glycerol oxidation
    When biomass is converted into biodiesel, huge amounts of glycerol are produced as a by-product. So far, however, this by-product has been little utilised, even though it could be processed into more valuable chemicals through oxidation in photoelectrochemical reactors. The reason for this: low efficiency and selectivity. A team led by Dr Marco Favaro from the Institute for Solar Fuels at HZB has now investigated the influence of electrolytes on the efficiency of the glycerol oxidation reaction. The results can help to develop more efficient and environmentally friendly production processes.
  • Small powerhouses for very special light
    Science Highlight
    27.06.2024
    Small powerhouses for very special light
    An international team presents the functional principle of a new source of synchrotron radiation in Nature Communications Physics. Steady-state microbunching (SSMB) allows to build efficient and powerful radiation sources for coherent UV radiation in the future. This is very attractive for applications in basic research as well in the semiconductor industry.
  • New Method for Absorption Correction to Improve Dental Fillings
    Science Highlight
    24.06.2024
    New Method for Absorption Correction to Improve Dental Fillings
    A research team led by Dr. Ioanna Mantouvalou has developed a method to more accurately depict the elemental distributions in dental materials than previously possible. The used confocal micro-X-ray fluorescence (micro-XRF) analysis provides three-dimensional elemental images that contain distortions. These distortions occur when X-rays pass through materials of different densities and compositions. By utilizing micro-CT data, which provides detailed 3D images of the material structure, and chemical information from X-ray absorption spectroscopy (XAS) experiments conducted in the laboratory (BLiX, TU Berlin) and at the synchrotron light source BESSY II, the researchers have improved the method.
  • MXenes for energy storage: Chemical imaging more than just surface deep
    Science Highlight
    17.06.2024
    MXenes for energy storage: Chemical imaging more than just surface deep
    A new method in spectromicroscopy significantly improves the study of chemical reactions at the nanoscale, both on surfaces and inside layered materials. Scanning X-ray microscopy (SXM) at MAXYMUS beamline of BESSY II enables the investigation of chemical species adsorbed on the top layer (surface) or intercalated within the MXene electrode (bulk) with high chemical sensitivity. The method was developed by a HZB team led by Dr. Tristan Petit. The scientists demonstrated among others first SXM on MXene flakes, a material used as electrode in lithium-ion batteries.
  • Alkanes, laser flashes and BESSY's X-ray vision
    Science Highlight
    31.05.2024
    Alkanes, laser flashes and BESSY's X-ray vision
    An international research team has succeeded in observing an intermediate step in the catalysis of alkanes. By understanding these reactions, existing catalysts can be optimized in the future and new ones found, for example to convert the greenhouse gas methane into valuable raw materials for industry.

  • Freeze casting - a guide to creating hierarchically structured materials
    Science Highlight
    25.04.2024
    Freeze casting - a guide to creating hierarchically structured materials
    Freeze casting is an elegant, cost-effective manufacturing technique to produce highly porous materials with custom-designed hierarchical architectures, well-defined pore orientation, and multifunctional surface structures. Freeze-cast materials are suitable for many applications, from biomedicine to environmental engineering and energy technologies. An article in "Nature Reviews Methods Primer" now provides a guide to freeze-casting methods that includes an overview on current and future applications and highlights characterization techniques with a focus on X-ray tomoscopy.
  • IRIS beamline at BESSY II extended with nanomicroscopy
    Science Highlight
    25.04.2024
    IRIS beamline at BESSY II extended with nanomicroscopy
    The IRIS infrared beamline at the BESSY II storage ring now offers a fourth option for characterising materials, cells and even molecules on different length scales. The team has extended the IRIS beamline with an end station for nanospectroscopy and nanoimaging that enables spatial resolutions down to below 30 nanometres. The instrument is also available to external user groups. 

  • A simpler way to inorganic perovskite solar cells
    Science Highlight
    17.04.2024
    A simpler way to inorganic perovskite solar cells
    Inorganic perovskite solar cells made of CsPbI3 are stable over the long term and achieve good efficiencies. A team led by Prof. Antonio Abate has now analysed surfaces and interfaces of CsPbI3 films, produced under different conditions, at BESSY II. The results show that annealing in ambient air does not have an adverse effect on the optoelectronic properties of the semiconductor film, but actually results in fewer defects. This could further simplify the mass production of inorganic perovskite solar cells.
  • Spintronics: A new path to room temperature swirling spin textures
    Science Highlight
    16.04.2024
    Spintronics: A new path to room temperature swirling spin textures
    A team at HZB has investigated a new, simple method at BESSY II that can be used to create stable radial magnetic vortices in magnetic thin films.

  • BESSY II: How pulsed charging enhances the service time of batteries
    Science Highlight
    08.04.2024
    BESSY II: How pulsed charging enhances the service time of batteries
    An improved charging protocol might help lithium-ion batteries to last much longer. Charging with a high-frequency pulsed current reduces ageing effects, an international team demonstrated. The study was led by Philipp Adelhelm (HZB and Humboldt University) in collaboration with teams from the Technical University of Berlin and Aalborg University in Denmark. Experiments at the X-ray source BESSY II were particularly revealing.
  • Fuel Cells: Oxidation processes of phosphoric acid revealed by tender X-rays
    Science Highlight
    03.04.2024
    Fuel Cells: Oxidation processes of phosphoric acid revealed by tender X-rays
    The interactions between phosphoric acid and the platinum catalyst in high-temperature PEM fuel cells are more complex than previously assumed. Experiments at BESSY II with tender X-rays have decoded the multiple oxidation processes at the platinum-electrolyte interface. The results indicate that variations in humidity can influence some of these processes in order to increase the lifetime and efficiency of fuel cells. 
  • Where quantum computers can score
    Science Highlight
    15.03.2024
    Where quantum computers can score
    The travelling salesman problem is considered a prime example of a combinatorial optimisation problem. Now a Berlin team led by theoretical physicist Prof. Dr. Jens Eisert of Freie Universität Berlin and HZB has shown that a certain class of such problems can actually be solved better and much faster with quantum computers than with conventional methods.
  • The future of BESSY
    News
    07.03.2024
    The future of BESSY
    At the end of February 2024, a team at HZB published an article in Synchrotron Radiation News (SRN). They describe the next development goals for the light source as well as the BESSY II+ upgrade programme and the successor source BESSY III.

  • Unconventional piezoelectricity in ferroelectric hafnia
    Science Highlight
    26.02.2024
    Unconventional piezoelectricity in ferroelectric hafnia
    Hafnium oxide thin films are a fascinating class of materials with robust ferroelectric properties in the nanometre range. While their ferroelectric behaviour is extensively studied, results on piezoelectric effects have so far remained mysterious. A new study now shows that the piezoelectricity in ferroelectric Hf0.5Zr0.5O2 thin films can be dynamically changed by electric field cycling. Another ground-breaking result is a possible occurrence of an intrinsic non-piezoelectric ferroelectric compound. These unconventional features in hafnia offer new options for use in microelectronics and information technology.
  • 14 parameters in one go: New instrument for optoelectronics
    Science Highlight
    21.02.2024
    14 parameters in one go: New instrument for optoelectronics
    An HZB physicist has developed a new method for the comprehensive characterisation of semiconductors in a single measurement. The "Constant Light-Induced Magneto-Transport (CLIMAT)" is based on the Hall effect and allows to record 14 different parameters of transport properties of negative and positive charge carriers. The method was tested now on twelve different semiconductor materials and will save valuable time in assessing new materials for optoelectronic applications such as solar cells.
  • Sodium-ion batteries: How doping works
    Science Highlight
    20.02.2024
    Sodium-ion batteries: How doping works
    Sodium-ion batteries still have a number of weaknesses that could be remedied by optimising the battery materials. One possibility is to dope the cathode material with foreign elements. A team from HZB and Humboldt-Universität zu Berlin has now investigated the effects of doping with Scandium and Magnesium. The scientists collected data at the X-ray sources BESSY II, PETRA III, and SOLARIS to get a complete picture and uncovered two competing mechanisms that determine the stability of the cathodes.
  • BESSY II: Molecular orbitals determine stability
    Science Highlight
    07.02.2024
    BESSY II: Molecular orbitals determine stability
    Carboxylic acid dianions (fumarate, maleate and succinate) play a role in coordination chemistry and to some extent also in the biochemistry of body cells. An HZB team at BESSY II has now analysed their electronic structures using RIXS in combination with DFT simulations. The results provide information not only on electronic structures but also on the relative stability of these molecules which can influence an industry's choice of carboxylate dianions, optimizing both the stability and geometry of coordination polymers.
  • BESSY II: Local variations in the structure of High-Entropy Alloys
    Science Highlight
    30.01.2024
    BESSY II: Local variations in the structure of High-Entropy Alloys
    High-entropy alloys can withstand extreme heat and stress, making them suitable for a variety of specific applications. A new study at the X-ray synchrotron radiation source BESSY II has now provided deeper insights into the ordering processes and diffusion phenomena in these materials. The study involved teams from HZB, the Federal Institute for Materials Research and Testing, the University of Latvia and the University of Münster.
  • Higher measurement accuracy opens new window to the quantum world
    Science Highlight
    17.01.2024
    Higher measurement accuracy opens new window to the quantum world
    A team at HZB has developed a new measurement method that, for the first time, accurately detects tiny temperature differences in the range of 100 microkelvin in the thermal Hall effect. Previously, these temperature differences could not be measured quantitatively due to thermal noise. Using the well-known terbium titanate as an example, the team demonstrated that the method delivers highly reliable results. The thermal Hall effect provides information about coherent multi-particle states in quantum materials, based on their interaction with lattice vibrations (phonons).
  • Green hydrogen: Perovskite oxide catalysts analysed in an X-ray beam
    Science Highlight
    21.12.2023
    Green hydrogen: Perovskite oxide catalysts analysed in an X-ray beam
    The production of green hydrogen requires catalysts that control the process of splitting water into oxygen and hydrogen. However, the structure of the catalyst changes under electrical tension, which also influences the catalytic activity. A team from the universities of Duisburg-Essen and Twente has investigated at BESSY II and elsewhere how the transformation of surfaces in perovskite oxide catalysts controls the activity of the oxygen evolution reaction. 
  • Green hydrogen: Improving iridium catalysts with titanium oxides
    Science Highlight
    13.12.2023
    Green hydrogen: Improving iridium catalysts with titanium oxides
    Anodes for the electrolytic splitting of water are usually iridium-based materials. In order to increase the stability of the iridium catalyst, a team at HZB and a group at HI-ERN have now produced a so-called material library: a sample in which the concentration of iridium and titanium oxides is systematically varied. Analyses of the individual sample segments at BESSY II in the EMIL laboratory showed that the presence of titanium oxides can increase the stability of the iridium catalyst significantly.
  • HZB-Highlights 2022 published
    News
    12.12.2023
    HZB-Highlights 2022 published
    The Highlights 2022 report on a selection of the most important research results and events at HZB.
  • BESSY II: Neutralising electronic inhomogeneity in cleaved bulk MoS₂
    Science Highlight
    30.10.2023
    BESSY II: Neutralising electronic inhomogeneity in cleaved bulk MoS₂
    Molybdenum disulphide (MoS₂) is a highly versatile material that can function, for example, as a gas sensor or as a photocatalyst in green hydrogen production. Although the understanding of a material usually starts from investigating its bulk crystalline form, for MoS₂ much more studies have been devoted to mono and few layer nanosheets. The few studies conducted thus far show diverse and irreproducible results for the electronic properties of cleaved bulk MoS₂ surfaces, highlighting the need for a more systematic study.
  • Diamond materials as solar-powered electrodes – spectroscopy shows what’s important
    Science Highlight
    08.10.2023
    Diamond materials as solar-powered electrodes – spectroscopy shows what’s important
    It sounds like magic: photoelectrodes could convert the greenhouse gas CO₂ back into methanol or N2 molecules into valuable fertiliser – using only the energy of sunlight. An HZB study has now shown that diamond materials are in principle suitable for such photoelectrodes. By combining X-ray spectroscopic techniques at BESSY II with other measurement methods, Tristan Petit’s team has succeeded for the first time in precisely tracking which processes are excited by light as well as the crucial role of the surface of the diamond materials.
  • Structure formation during freeze casting filmed
    Science Highlight
    06.09.2023
    Structure formation during freeze casting filmed
    Freeze casting processes can be used to produce highly porous and hierarchically structured materials that have a large surface area. They are suitable for a wide variety of applications, as electrodes for batteries, catalyst materials or in biomedicine. A team led by Prof. Ulrike G. K. Wegst, Northeastern University, Boston, MA, USA and Dr. Francisco García Moreno from the Helmholtz-Zentrum Berlin have used the newly developed X-ray tomoscopy technique. At the Swiss Light Source of the Paul Scherrer Institute they observed in real time and at high resolution how the process of structure formation takes place during freezing. A sugar solution served as the model system.
  • Quantum computing: Benchmarking performance by random data
    Science Highlight
    29.08.2023
    Quantum computing: Benchmarking performance by random data
    With increasing size and complexity, quantum computers become a sort of black box. Using methods from mathematical physics, a team has now succeeded in deriving concrete numbers from random, data sequences that can serve as a benchmark for the performance of a quantum computer system. Experts from Helmholtz-Zentrum Berlin, Freie Universität Berlin, Qusoft Research Centre Amsterdam, the University of Copenhagen and the Technology Innovation Institute Abu Dhabi were involved in the work, which has now been published in Nature Communications.
  • Spintronics: X-ray microscopy unravels the nature of domain walls
    Science Highlight
    28.08.2023
    Spintronics: X-ray microscopy unravels the nature of domain walls
    Magnetic skyrmions are tiny vortices of magnetic spin textures. In principle, materials with skyrmions could be used as spintronic devices, for example as very fast and energy-efficient data storage devices. But at the moment it is still difficult to control and manipulate skyrmions at room temperature. A new study at BESSY II analyses the formation of skyrmions in ferrimagnetic thin films of dysprosium and cobalt in real time and with high spatial resolution. This is an important step towards characterising suitable materials with skyrmions more precisely in the future.
  • BESSY II: Surface analysis of catalyst particles in aqueous solutions
    Science Highlight
    21.07.2023
    BESSY II: Surface analysis of catalyst particles in aqueous solutions
    In a special issue on the liquid jet method, a team reports on reactions of water molecules on the surfaces of metal oxide particles. The results are relevant for the development of efficient photoelectrodes for the production of green hydrogen.
  • Quantitative analysis of cell organelles with artificial intelligence
    Science Highlight
    18.07.2023
    Quantitative analysis of cell organelles with artificial intelligence
    X-ray microscopy (cryo-SXT) enables high-resolution insights into cells and cell organelles - in three dimensions. Until now, the 3D data sets have been analysed manually, which is very time-consuming. A team from Freie Universität Berlin has now developed a self-learning algorithm based on a convolutional neural network. In collaboration with experts in cell biology (FU Berlin) and X-ray microscopy at the Helmholtz Zentrum Berlin, this algorithm has now been used for the first time to analyse cell components in cryo-SXT data sets. It identified cell organelles and produced highly detailed, complex 3D images within a few minutes.
  • Solar hydrogen: Barriers for charge transport in metal oxides
    Science Highlight
    12.07.2023
    Solar hydrogen: Barriers for charge transport in metal oxides
    In theory, metal oxides are ideally suited as photoelectrodes for the direct generation of hydrogen with sunlight. Now, for the first time, a team at Helmholtz-Zentrum Berlin has succeeded in determining the transport properties of the charge carriers in different metal oxides over a time range of nine orders of magnitude.
  • Record-breaking tandem solar cell now with precise scientific explanations
    Science Highlight
    06.07.2023
    Record-breaking tandem solar cell now with precise scientific explanations
    The world's best tandem solar cells, consisting of a silicon bottom cell and a perovskite top cell, can today convert around one-third of incident solar radiation into electrical energy. These are record values, especially for a potentially very low-cost technology. A team at HZB is now providing the scientific data for the first time and describing how this development was achieved in the renowned journal Science. 
  • BESSY II: What drives ions through polymer membranes
    Science Highlight
    05.07.2023
    BESSY II: What drives ions through polymer membranes
    Photoelectrolysers and electrolysis cells can produce green hydrogen or fossil-free carbon compounds – but they require ion-exchange membranes. An HZB team has now studied the transport of ions through the membrane in a hybrid liquid gas electrolyzer at the X-ray source BESSY II. Contrary to expectations, however, concentration differences hardly drive electric field ions. Diffusion is therefore the decisive process. This finding could help in the development of highly efficient and significantly more environmentally friendly membrane materials.
  • Spintronics at BESSY II: Domain walls in magnetic nanowires
    Science Highlight
    02.06.2023
    Spintronics at BESSY II: Domain walls in magnetic nanowires
    Magnetic domains walls are known to be a source of electrical resistance due to the difficulty for transport electron spins to follow their magnetic texture. This phenomenon holds potential for utilization in spintronic devices, where the electrical resistance can vary based on the presence or absence of a domain wall. A particularly intriguing class of materials are half metals such as La2/3Sr1/3MnO3 (LSMO) which present full spin polarization, allowing their exploitation in spintronic devices. Still the resistance of a single domain wall in half metals remained unknown. Now a team from Spain, France and Germany has generated a single domain wall on a LSMO nanowire and measured resistance changes 20 times larger than for a normal ferromagnet such as Cobalt.
  • Fractons as information storage: Not yet quite tangible, but close
    Science Highlight
    26.05.2023
    Fractons as information storage: Not yet quite tangible, but close
    A new quasiparticle with interesting properties has appeared in solid-state physics - but so far only in the theoretical modelling of solids with certain magnetic properties. An international team from HZB and Freie Universität Berlin has now shown that, contrary to expectations, quantum fluctuations do not make the quasiparticle appear more clearly, but rather blur its signature.
  • Graphene on titanium carbide triggers a novel phase transition
    Science Highlight
    25.05.2023
    Graphene on titanium carbide triggers a novel phase transition
    Researchers have discovered a Lifshitz-transition in TiC, driven by a graphene overlayer, at the photon source BESSY II. Their study sheds light on the exciting potential of 2D materials such as graphene and the effects they can have on neighboring materials through proximity interactions.
  • Alexander von Humboldt Foundation Grant for Dr. Jie Wei
    News
    16.05.2023
    Alexander von Humboldt Foundation Grant for Dr. Jie Wei
    In April, Dr. Jie Wei started his research work in the Helmholtz Young Investigator Group Nanoscale Operando CO2 Photo-Electrocatalysis at Helmholtz-Zentrum Berlin (HZB) and Fritz Haber Institute (FHI) of the Max Planck Society. Wei received one of the highly competitive Humboldt postdoctoral research fellowships and will pursue his two-year project under the guidance of the academic hosts Dr. Christopher Kley and Prof. Dr. Beatriz Roldan Cuenya.
  • CO2 recycling: What is the role of the electrolyte?
    Science Highlight
    25.04.2023
    CO2 recycling: What is the role of the electrolyte?
    The greenhouse gas carbon dioxide can be converted into useful hydrocarbons by electrolysis. The design of the electrolysis cell is crucial in this process. The so-called zero-gap cell is particularly suitable for industrial processes. But there are still problems: The cathodes clog up quickly. At the HZB, Matthew Mayer and his team has now investigated what causes this and how this undesirable process can be prevented.
  • Fast and flexible solar energy from the printer
    News
    12.04.2023
    Fast and flexible solar energy from the printer
    Lighter, more flexible and adaptable – the innovation platform Solar TAP develops innovative solutions for photovoltaic applications. The aim is to make surfaces already used in agriculture, the building sector and transport additionally usable for the expansion of solar energy with printed solar cells.
  • How much cadmium is contained in cocoa beans?
    Science Highlight
    06.04.2023
    How much cadmium is contained in cocoa beans?
    Cocoa beans can absorb toxic heavy metals such as cadmium from the soil. Some cultivation areas, especially in South America, are polluted with these heavy metals, in some cases considerably. In combining different X-ray fluorescence techniques, a team at BESSY II has now been able to non-invasively measure for the first time where cadmium accumulates exactly in cocoa beans: Mainly in the shell. Further investigations show that the processing of the cocoa beans can have a great influence on the concentration of heavy metals.
  • Solid-State Lithium-Sulfur Batteries: Neutrons unveil sluggish charge transport
    Science Highlight
    05.04.2023
    Solid-State Lithium-Sulfur Batteries: Neutrons unveil sluggish charge transport
    Solid-state Lithium-Sulfur batteries offer the potential for much higher energy densities and increased safety, compared to conventional lithium-ion batteries. However, the performance of solid-state batteries is currently lacking, with slow charging and discharging being one of the primary causes. Now, a new study from HZB shows that sluggish lithium ion transport within a composite cathode is the cause of this slow charging and discharging.
  • Green hydrogen: How photoelectrochemical water splitting may become competitive
    Science Highlight
    20.03.2023
    Green hydrogen: How photoelectrochemical water splitting may become competitive
    Sunlight can be used to produce green hydrogen directly from water in photoelectrochemical (PEC) cells. So far, systems based on this "direct approach" have not been energetically competitive. However, the balance changes as soon as some of the hydrogen in such PEC cells is used in-situ for a catalytic hydrogenation reaction, resulting in the co-production of chemicals used in the chemical and pharmaceutical industries. The energy payback time of photoelectrochemical "green" hydrogen production can be reduced dramatically, the study shows.
  • Perovskite solar cells from the slot die coater - a step towards industrial production
    Science Highlight
    16.03.2023
    Perovskite solar cells from the slot die coater - a step towards industrial production
    Solar cells made from metal halide perovskites achieve high efficiencies and their production from liquid inks requires only a small amount of energy. A team led by Prof. Dr. Eva Unger at Helmholtz-Zentrum Berlin is investigating the production process. At the X-ray source BESSY II, the group has analyzed the optimal composition of precursor inks for the production of high-quality FAPbI3 perovskite thin films by slot-die coating. The solar cells produced with these inks were tested under real life conditions in the field for a year and scaled up to mini-module size.
  • Superstore MXene: New proton hydration structure determined
    Science Highlight
    13.03.2023
    Superstore MXene: New proton hydration structure determined
    MXenes are able to store large amounts of electrical energy like batteries and to charge and discharge rather quickly like a supercapacitor. They combine both talents and thus are a very interesting class of materials for energy storage. The material is structured like a kind of puff pastry, with the MXene layers separated by thin water films. A team at HZB has now investigated how protons migrate in the water films confined between the layers of the material and enable charge transport. Their results have been published in the renowned journal Nature Communications and may accelerate the optimisation of these kinds of energy storage materials.
  • Electrocatalysis under the atomic force microscope
    Science Highlight
    09.03.2023
    Electrocatalysis under the atomic force microscope
    A further development in atomic force microscopy now makes it possible to simultaneously image the height profile of nanometre-fine structures as well as the electric current and the frictional force at solid-liquid interfaces. A team from the Helmholtz-Zentrum Berlin (HZB) and the Fritz Haber Institute (FHI) of the Max Planck Society has succeeded in analysing electrocatalytically active materials and gaining insights that will help optimise catalysts. The method is also potentially suitable for studying processes on battery electrodes, in photocatalysis or on active biomaterials.
  • Electrocatalysis – Iron and Cobalt Oxyhydroxides examined at BESSY II
    Science Highlight
    16.02.2023
    Electrocatalysis – Iron and Cobalt Oxyhydroxides examined at BESSY II
    A team led by Dr. Prashanth W. Menezes (HZB/TU-Berlin) has now gained insights into the chemistry of one of the most active anode catalysts for green hydrogen production. They examined a series of Cobalt-Iron Oxyhydroxides at BESSY II and were able to determine the oxidation states of the active elements in different configurations as well as to unveil the geometrical structure of the active sites. Their results might contribute to the knowledge based design of new highly efficient and low cost catalytical active materials.
  • Stability of perovskite solar cells reaches next milestone
    Science Highlight
    27.01.2023
    Stability of perovskite solar cells reaches next milestone
    Perovskite semiconductors promise highly efficient and low-cost solar cells. However, the semi-organic material is very sensitive to temperature differences, which can quickly lead to fatigue damage in normal outdoor use. Adding a dipolar polymer compound to the precursor perovskite solution helps to counteract this. This has now been shown in a study published in the journal Science by an international team led by Antonio Abate, HZB. The solar cells produced in this way achieve efficiencies of well above 24 %, which hardly drop under rapid temperature fluctuations between -60 and +80 Celsius over one hundred cycles. That corresponds to about one year of outdoor use.
  • Recommended reading: Bunsen magazine with focus on molecular water research
    News
    13.01.2023
    Recommended reading: Bunsen magazine with focus on molecular water research
    Water not only has some well-known anomalies, but is still full of surprises. The first issue 2023 of the Bunsen Magazine is dedicated to molecular water research, from the ocean to processes in electrolysis. The issue presents contributions from researchers cooperating within the framework of a European research initiative in the "Centre for Molecular Water Science" (CMWS). A team at HZB presents results from the synchrotron spectroscopy of water. Modern X-ray sources can be used to study molecular and electronic processes in water in detail.
  • New software based on Artificial Intelligence helps to interpret complex data
    Science Highlight
    20.12.2022
    New software based on Artificial Intelligence helps to interpret complex data
    Experimental data is often not only highly dimensional, but also noisy and full of artefacts. This makes it difficult to interpret the data. Now a team at HZB has designed software that uses self-learning neural networks to compress the data in a smart way and reconstruct a low-noise version in the next step. This enables to recognise correlations that would otherwise not be discernible. The software has now been successfully used in photon diagnostics at the FLASH free electron laser at DESY. But it is suitable for very different applications in science.
  • World record back at HZB: Tandem solar cell achieves 32.5 percent efficiency
    News
    19.12.2022
    World record back at HZB: Tandem solar cell achieves 32.5 percent efficiency
    The current world record of tandem solar cells consisting of a silicon bottom cell and a perovskite top cell is once again at HZB. The new tandem solar cell converts 32.5 % of the incident solar radiation into electrical energy. The certifying institute European Solar Test Installation (ESTI) in Italy measured the tandem cell and officially confirmed this value which is also included in the NREL chart of solar cell technologies, maintained by the National Renewable Energy Lab, USA.
  • New monochromator optics for tender X-rays
    Science Highlight
    30.11.2022
    New monochromator optics for tender X-rays
    Until now, it has been extremely tedious to perform measurements with high sensitivity and high spatial resolution using X-ray light in the tender energy range of 1.5 - 5.0 keV. Yet this X-ray light is ideal for investigating energy materials such as batteries or catalysts, but also biological systems. A team from HZB has now solved this problem: The newly developed monochromator optics increase the photon flux in the tender energy range by a factor of 100 and thus enable highly precise measurements of nanostructured systems. The method was successfully tested for the first time on catalytically active nanoparticles and microchips.
  • Nanodiamonds can be activated as photocatalysts with sunlight
    Science Highlight
    30.11.2022
    Nanodiamonds can be activated as photocatalysts with sunlight
    Nanodiamond materials have potential as low-cost photocatalysts. But until now, such carbon nanoparticles required high-energy UV light to become active. The DIACAT consortium has therefore produced and analysed variations of nanodiamond materials. The work shows: If the surface of the nanoparticles is occupied by sufficient hydrogen atoms, even the weaker energy of blue sunlight is sufficient for excitation. Future photocatalysts based on nanodiamonds might be able to convert CO2 or N2 into hydrocarbons or ammonia with sunlight.
  • Tomography shows high potential of copper sulphide solid-state batteries
    Science Highlight
    28.11.2022
    Tomography shows high potential of copper sulphide solid-state batteries
    Solid-state batteries enable even higher energy densities than lithium-ion batteries with high safety. A team led by Prof. Philipp Adelhelm and Dr. Ingo Manke succeeded in observing a solid-state battery during charging and discharging and creating high-resolution 3D images. This showed that cracking can be effectively reduced through higher pressure.

  • Quantum algorithms save time in the calculation of electron dynamics
    Science Highlight
    22.11.2022
    Quantum algorithms save time in the calculation of electron dynamics
    Quantum computers promise significantly shorter computing times for complex problems. But there are still only a few quantum computers worldwide with a limited number of so-called qubits. However, quantum computer algorithms can already run on conventional servers that simulate a quantum computer. A team at HZB has succeeded to calculate the electron orbitals and their dynamic development on the example of a small molecule after a laser pulse excitation. In principle, the method is also suitable for investigating larger molecules that cannot be calculated using conventional methods.
  • How photoelectrodes change in contact with water
    Science Highlight
    17.11.2022
    How photoelectrodes change in contact with water
    Photoelectrodes based on BiVO4 are considered top candidates for solar hydrogen production. But what exactly happens when they come into contact with water molecules? A study in the Journal of the American Chemical Society has now partially answered this crucial question:  Excess electrons from dopants or defects aid the dissociation of water which in turn stabilizes so-called polarons at the surface. This is shown by data from experiments conducted at the Advanced Light Source at Lawrence Berkeley National Laboratory. These insights might foster a knowledge-based design of better photoanodes for green hydrogen production.
  • A perfect match: perovskite meets perovskite
    Interview
    07.11.2022
    A perfect match: perovskite meets perovskite
    Tandem solar cells, which combine two different perovskite semiconductors, promise high efficiencies and can be produced with very little energy input. Such modules could even be bendable. Together with partners from industry and research, HZB expert Prof. Steve Albrecht is working to realise this vision. His team recently succeeded in producing an all-perovskite tandem solar cell with a certified efficiency of 27.2 %. A conversation about the opportunities and challenges of the perovskite-perovskite technology.
  • Batteries without critical raw materials
    Science Highlight
    26.10.2022
    Batteries without critical raw materials
    The market for rechargeable batteries is growing rapidly, but the necessary raw materials are limited. Sodium-ion batteries, for example, could offer an alternative. A joint research group from HZB and Humboldt-Universität zu Berlin has investigated new combinations of electrolyte solutions and electrode materials for this purpose.
  • Tandem solar cells with perovskite: nanostructures help in many ways
    Science Highlight
    24.10.2022
    Tandem solar cells with perovskite: nanostructures help in many ways
    By the end of 2021, teams at HZB had presented perovskite silicon tandem solar cells with an efficiency close to 30 percent. This value was a world record for eight months, a long time for this hotly contested field of research. In the renowned journal Nature Nanotechnology, the scientists describe how they achieved this record value with nanooptical structuring and reflective coatings.
  • Spintronics: A new tool at BESSY II for chirality investigations
    Science Highlight
    24.10.2022
    Spintronics: A new tool at BESSY II for chirality investigations
    Information on complex magnetic structures is crucial to understand and develop spintronic materials. Now, a new instrument named ALICE II is available at BESSY II. It allows magnetic X-ray scattering in reciprocal space using a new large area detector. A team at HZB and Technical University Munich has demonstrated the performance of ALICE II by analysing helical and conical magnetic states of an archetypal single crystal skyrmion host. ALICE II is now available for guest users at BESSY II.
  • High entropy alloys: structural disorder and magnetic properties
    Science Highlight
    20.10.2022
    High entropy alloys: structural disorder and magnetic properties
    High-entropy alloys (HEAs) are promising materials for catalysis and energy storage, and at the same time they are extremely hard, heat resistant and demonstrate great variability in their magnetic behaviour. Now, a team at BESSY II in collaboration with Ruhr University Bochum, BAM, Freie Universität Berlin and University of Latvia has gained new insights into the local environment of a so-called high-entropy Cantor alloy made of chromium, manganese, iron, cobalt and nickel, and has thus also been able to partially explain the magnetic properties of a nanocrystalline film of this alloy.
  • Green hydrogen: faster progress with modern X-ray sources
    Science Highlight
    07.10.2022
    Green hydrogen: faster progress with modern X-ray sources
    In order to produce green hydrogen, water can be split up via electrocatalysis, powered by renewable sources such as sun or wind. A review article in the journal Angewandte Chemie Int. Ed. shows how modern X-ray sources such as BESSY II can advance the development of suitable electrocatalysts. In particular, X-ray absorption spectroscopy can be used to determine the active states of catalytically active materials for the oxygen evolution reaction. This is an important contribution to developing efficient catalysts from inexpensive and widely available elements.
  • BESSY II: Localisation of d-electrons determined
    Science Highlight
    02.10.2022
    BESSY II: Localisation of d-electrons determined
    Transition metals have many applications in engineering, electrochemistry and catalysis. To understand their properties, the interplay between atomic localisation and delocalisation of the outer electrons in the d orbitals is crucial. This insight is now provided by a special end station at BESSY II with highest precision, as demonstrated by a study of copper, nickel and cobalt with interesting quantitative results. The Royal Society of Chemistry has selected the paper as a HOT Article 2022.
  • Rhombohedral graphite as a model for quantum magnetism
    Science Highlight
    27.09.2022
    Rhombohedral graphite as a model for quantum magnetism
    Graphene is an extremely exciting material. Now a graphene variant shows another talent: rhombohedral graphite made of several layers slightly offset from each other could enlighten the hidden physics in quantum magnets.
  • New road towards spin-polarised currents
    Science Highlight
    08.09.2022
    New road towards spin-polarised currents
    The transition metal dichalcogenide (TMD) series are a family of promising candidate materials for spintronics. A study at lightsource BESSY II has unveiled that in one of those materials even simple linear polarised light is sufficient to selectively manipulate spins of different orientations. This result provides an entirely new route for the generation of spin-polarised currents and is a milestone for the development of spintronic and opto-spintronic devices.
  • Buckyballs on gold are less exotic than graphene
    Science Highlight
    21.07.2022
    Buckyballs on gold are less exotic than graphene
    C60 molecules on a gold substrate appear more complex than their graphene counterparts, but have much more ordinary electronic properties. This is now shown by measurements with ARPES at BESSY II and detailed calculations.
  • Third-highest oxidation state secures rhodium a place on the podium
    Science Highlight
    14.07.2022
    Third-highest oxidation state secures rhodium a place on the podium
    Oxidation states of transition metals describe how many electrons of an element are already engaged in bonding, and how many are still available for further reactions. Scientists from Berlin and Freiburg have now discovered the highest oxidation state of rhodium, indicating that rhodium can involve more of its valence electrons in chemical bonding than previously thought. This finding might be relevant for the understanding of catalytic reactions involving highly-oxidized rhodium. The result was recognized as a „very important paper“ in Angewandte Chemie.

  • Potential energy surfaces of water mapped for the first time
    Science Highlight
    07.07.2022
    Potential energy surfaces of water mapped for the first time
    Liquids are more difficult to describe than gases or crystalline solids. An HZB team has now mapped the potential energy surfaces of water molecules in liquid water under ambient conditions for the first time at the Swiss Light Source SLS of the Paul Scherrer Institute, Switzerland. This contributes to a better understanding of the chemistry of water and in aqueous solutions. These investigations can soon be continued at the newly built METRIXS station at the X-ray source BESSY II.
  • Spintronics: Giant Rashba semiconductors show unconventional dynamics with potential applications
    Science Highlight
    06.07.2022
    Spintronics: Giant Rashba semiconductors show unconventional dynamics with potential applications
    Germanium telluride is a strong candidate for use in functional spintronic devices due to its giant Rashba-effect. Now, scientists at HZB have discovered another intriguing phenomenon in GeTe by studying the electronic response to thermal excitation of the samples. To their surprise, the subsequent relaxation proceeded fundamentally different to that of conventional semimetals. By delicately controlling the fine details of the underlying electronic structure, new functionalities of this class of materials could be conceived. 

  • Atomic displacements in High-Entropy Alloys examined
    Science Highlight
    27.06.2022
    Atomic displacements in High-Entropy Alloys examined
    High-entropy alloys of 3d metals have intriguing properties that are interesting for applications in the energy sector. An international team at BESSY II has now investigated the local order on an atomic scale in a so-called high-entropy Cantor alloy of chromium, manganese, iron, cobalt and nickel. The results from combined spectroscopic studies and statistical simulations expand the understanding of this group of materials.
  • Calculating the "fingerprints" of molecules with artificial intelligence
    Science Highlight
    13.06.2022
    Calculating the "fingerprints" of molecules with artificial intelligence
    With conventional methods, it is extremely time-consuming to calculate the spectral fingerprint of larger molecules. But this is a prerequisite for correctly interpreting experimentally obtained data. Now, a team at HZB has achieved very good results in significantly less time using self-learning graphical neural networks.
  • Water distribution in the fuel cell made visible in 4D
    Science Highlight
    02.06.2022
    Water distribution in the fuel cell made visible in 4D
    Teams from Helmholtz-Zentrum Berlin (HZB) and University College London (UCL) have visualised the water distribution in a fuel cell in three dimensions and in real time for the first time by evaluating neutron data from the Berlin Experimental Reactor shut down in 2019. The analysis opens new possibilities for more efficient and thus more cost-effective fuel cells.
  • Thermal insulation for quantum technologies
    Science Highlight
    19.05.2022
    Thermal insulation for quantum technologies
    New energy-efficient IT components often only operate stably at extremely low temperatures. Therefore, very good thermal insulation of such elements is crucial, which requires the development of materials with extremely low thermal conductivity. A team at HZB has now used a novel sintering process to produce nanoporous silicon aluminium samples in which pores and nanocrystallites impede the transport of heat and thus drastically reduce thermal conductivity. The researchers have developed a model for predicting the thermal conductivity, which was confirmed using experimental data on the microstructure of the samples and their thermal conductivity. Thus, for the first time, a method is available for the targeted development of complex porous materials with ultra-low thermal conductivity.
  • Magnetic nanoparticles in biological vehicles individually characterised
    Science Highlight
    17.05.2022
    Magnetic nanoparticles in biological vehicles individually characterised
    Magnetic nanostructures are promising tools for medical applications.  Incorporated into biological structures, they can be steered via external magnetic fields inside the body to release drugs or to destroy cancer cells. However, until now, only average information on the magnetic properties of those nanoparticles could be obtained, thus limiting their successful implementations in therapies. Now a team at HZB conceived and tested a new method to assess the characteristic parameters of every single magnetic nanoparticle.
  • Jan Lüning heads HZB Institute for Electronic Structure Dynamics
    News
    09.05.2022
    Jan Lüning heads HZB Institute for Electronic Structure Dynamics
    The HZB Institute for Electronic Structure Dynamics, newly founded on 1 May, develops experimental techniques and infrastructures to investigate the dynamics of elementary microscopic processes in novel material systems. This will help to optimise functional materials for sustainable technologies.
  • How electron spin coupling affects catalytic oxygen activation
    Science Highlight
    09.05.2022
    How electron spin coupling affects catalytic oxygen activation
    A team at the EPR4Energy joint lab of HZB and MPI CEC has developed a new THz EPR spectroscopy method to study the catalytic activation of molecular oxygen by copper complexes. The method allows insights into previously inaccessible spin-spin interactions and the function of novel catalytic and magnetic materials.
  • Perovskite solar cells: Properties still remain enigmatic
    Science Highlight
    02.05.2022
    Perovskite solar cells: Properties still remain enigmatic
    In order to explain the particularly favourable properties of perovskite semiconductors for solar cells, various hypotheses are circulating. Polarons or a giant Rashba effect, for example, are thought to play a major role. A team at BESSY II has now experimentally disproved these hypotheses. In doing so, they further narrow down the possible causes for the transport properties and enable better approaches for the targeted optimisation of this class of materials.
  • Solar hydrogen: Better photoelectrodes through flash heating
    Science Highlight
    04.04.2022
    Solar hydrogen: Better photoelectrodes through flash heating
    Producing low-cost metal-oxide thin films with high electronic quality for solar water splitting is not an easy task. Especially since quality improvements of the upper metal oxide thin films need thermal processing at high temperatures, which would melt the underlying glass substrate. Now, a team at HZB-Institute for Solar Fuels has solved this dilemma: A high intensity and rapid light pulse directly heats the semiconducting metal-oxide thin film, allowing to achieve the optimal heating conditions without damaging the substrate.
  • Unravelling tautomeric mixtures: RIXS at BESSY II allows to see clearly
    Science Highlight
    17.03.2022
    Unravelling tautomeric mixtures: RIXS at BESSY II allows to see clearly
    A team at HZB has developed a method of experimentally unravelling tautomeric mixtures. Based on resonant inelastic X-ray scattering (RIXS) at BESSY II, not only proportions of the tautomers can be deduced, but the properties of each individual tautomer can be studied selectively. This method could yield to detailed information on the properties of molecules and their biological function. In the present study, now advertised on the cover of “The Journal of Physical Chemistry Letters” the technique was applied to the prototypical keto-enol equilibrium.
  • "We can be proud that it worked out": BESSY and the Transregio-SFB on ultrafast spin dynamics
    Interview
    14.03.2022
    "We can be proud that it worked out": BESSY and the Transregio-SFB on ultrafast spin dynamics

    Collaborative Research projects as “Sonderforschungsbereiche” funded by Deutsche Forschungsgemeinschaft enable universities to build up their own research capacities. In the Transregio Sonderforschungsbereich 227 Ultrafast Spin Dynamic, the Freie Universität Berlin and the University in Halle-Wittenberg have also included HZB as a partner. The slicing facility of BESSY II plays a central role in this collaboration. With excellent results from the first phase, the Transregio-SFB 227 has completed its first interim review and is now preparing for the challenges ahead. A conversation with the two HZB physicists Niko Pontius and Christian Schüßler-Langeheine about the importance of such funding programmes for the research field.

  • Predicting solar cell performance from terahertz and microwave spectroscopy
    Science Highlight
    04.03.2022
    Predicting solar cell performance from terahertz and microwave spectroscopy
    Many semiconducting materials are possible candidates for solar cells. In recent years, perovskite semiconductors in particular have attracted attention, as they are both inexpensive and easy to process and enable high efficiencies. Now a study with 15 participating research institutions shows how terahertz (TRTS) and microwave spectroscopy (TRMC) can be used to reliably determine the mobility and lifetime of the charge carriers in new semiconducting materials. Using these measurement data it is possible to predict the potential efficiency of the solar cell in advance and to classify the losses in the finished cell.  
  • “Workhorse” of silicon photovoltaics combined with perovskite in tandem for the first time
    Science Highlight
    24.02.2022
    “Workhorse” of silicon photovoltaics combined with perovskite in tandem for the first time
    So-called PERC cells are used in mass production of silicon solar cells, they are considered the workhorses of photovoltaics, dominating the market. Now two teams from HZB and the Institute for Solar Energy Research in Hamelin (ISFH) have shown that such standard silicon cells are also suitable as a basis for tandem cells with perovskite top cells. Currently, the efficiency of the tandem cell is still below that of optimised PERC cells alone, but could be increased to up to 29.5% through targeted optimisation. The research was funded by the German Federal Ministry of Economics as part of a joint project.
  • Lithium-Sulfur batteries: First multimodal analysis in pouch cell format
    Science Highlight
    21.02.2022
    Lithium-Sulfur batteries: First multimodal analysis in pouch cell format
    Lithium-sulphur (Li/S) batteries have significantly higher energy densities than conventional lithium-ion batteries, but age very quickly. Now, for the first time, a team at HZB has investigated Li/S batteries in the industry-relevant pouch cell format with different electrolytes during operation. Teams from TU Dresden and the Fraunhofer IWS were also involved in the study. With a specially developed measuring cell, impedance, temperature and pressure can be recorded at different times and combined with radiographic images. The evaluation shows how the electrolyte affects the formation of unwanted sulphur particles and polysulphides. The study has been published in the renowned journal Advanced Energy Materials.
  • Innovative catalysts: An expert review
    Science Highlight
    15.02.2022
    Innovative catalysts: An expert review
    Highly efficient (electro-)catalysts are essential for the production of green hydrogen, the chemical industry, fertiliser production and other sectors of the economy. In addition to transition metals, a variety of other metallic or non-metallic elements have now moved into the focus of research. In a review article, experts from CatLab and Technische Universität Berlin present an overview on current knowledge and a perspective on future research questions.
  • A sundial of a different kind
    Interview
    24.01.2022
    A sundial of a different kind
    Turning a scientific question into a product is the requirement that the winners of the HZB Technology Transfer Prize should fulfil. The team led by Tobias Henschel, Bernd Stannowski and Sebastian Neubert won more than just a prize.
  • An electronic rainbow – perovskite spectrometer by inkjet printing
    Science Highlight
    20.12.2021
    An electronic rainbow – perovskite spectrometer by inkjet printing
    Researchers from Innovation Lab HySPRINT at Helmholtz-Zentrum Berlin (HZB) and Humboldt Universität zu Berlin (HU) have used an advanced inkjet printing technique to produce a large range of photodetector devices based on a hybrid perovskite semiconductor. By mixing of only three inks, the researchers were able to precisely tune the semiconductor properties during the printing process. Inkjet printing is already an established fabrication method in industry, allowing fast and cheap solution processing. Extending the inkjet capabilities from large area coating towards combinatorial material synthesis opens the door for new possibilities for the fabrication of different kind of electronic components in a single printing step.
  • A Wiki for Perovskite Solar Cell Research
    Science Highlight
    15.12.2021
    A Wiki for Perovskite Solar Cell Research
    An international team of experts has collected data on metal halide perovskite solar cells from more than 15,000 publications and developed a database with visualisation options and analysis tools. The database is open source and provides an overview of the rapidly growing knowledge as well as the open questions in this exciting class of materials. The study was initiated by HZB scientist Dr. Eva Unger and implemented and coordinated by her postdoc Jesper Jacobsson.
  • Green information technologies: Superconductivity meets Spintronics
    Science Highlight
    02.12.2021
    Green information technologies: Superconductivity meets Spintronics
    Superconducting coupling between two regions separated by a one micron wide ferromagnetic compound has been proved by an international team. This macroscopic quantum effect, known as Josephson effect, generates an electrical current within the ferromagnetic compound made of superconducting Cooper-pairs. Magnetic imaging of the ferromagnetic region at BESSY II has contributed to demonstrate that the spin of the electrons forming the Cooper pairs are equal. These results pave the way for low-power consumption superconducting spintronic-applications where spin-polarized currents can be protected by quantum coherence.

  • Neutron data help to reveal “spooky” entanglement in quantum magnets
    Science Highlight
    25.11.2021
    Neutron data help to reveal “spooky” entanglement in quantum magnets
    Using data from the British neutron source ISIS from the year 2000, research teams have now demonstrated the viability of a “quantum entanglement witness” capable of proving the presence of entanglement between magnetic particles, or spins, in a quantum material. A team from HZB led by Prof. Bella Lake was also involved in the analysis.
  • World record again at HZB: Almost 30 % efficiency for next-generation tandem solar cells
    News
    22.11.2021
    World record again at HZB: Almost 30 % efficiency for next-generation tandem solar cells
    Three HZB teams led by Prof. Christiane Becker, Prof. Bernd Stannowski and Prof. Steve Albrecht have jointly managed to increase the efficiency of perovskite silicon tandem solar cells fabricated completely at HZB to a new record value of 29.80 %. The value has now been officially certified and is documented in the NREL-charts. This brings the 30 percent mark within reach.

  • Professorship for Antonio Abate at Bielefeld University
    News
    03.11.2021
    Professorship for Antonio Abate at Bielefeld University
    Dr. Antonio Abate investigates perovskite semiconductors for low-cost and highly efficient solar cells and heads a large research group at the Helmholtz Centre Berlin. Now he has accepted a W2 professorship in the Department of Chemistry at Bielefeld University.

  • Spintronics: Exotic ferromagnetic order in two-dimensions
    Science Highlight
    29.10.2021
    Spintronics: Exotic ferromagnetic order in two-dimensions
    An international team has detected at HZB's vector magnet facility VEKMAG an unusual ferromagnetic property in a two-dimensional system, known as “easy-plane anisotropy”. This could foster new energy efficient information technologies based on spintronics for data storage, among other things. The team has published its results in the renowned journal Science.

  • Ultrafast magnetism: heating magnets, freezing time
    Science Highlight
    15.10.2021
    Ultrafast magnetism: heating magnets, freezing time
    Magnetic solids can be demagnetized quickly with a short laser pulse, and there are already so-called HAMR (Heat Assisted Magnetic Recording) memories on the market that function according to this principle. However, the microscopic mechanisms of ultrafast demagnetization remain unclear. Now, a team at HZB has developed a new method at BESSY II to quantify one of these mechanisms and applied it to the rare-earth element Gadolinium, whose magnetic properties are caused by electrons on both the 4f and the 5d shells. This study is completing a series of experiments done by the team on Nickel, Iron-Nickel Alloys. Understanding these mechanisms is useful for developing ultrafast data storage devices.

  • Perovskite solar cells: Defects trap charge carriers - and release them again
    Science Highlight
    07.10.2021
    Perovskite solar cells: Defects trap charge carriers - and release them again
    An international team at HZB and Charles University Prague has investigated how charge carriers in so called MAPI-perovskite semiconductors interact with different defects. They show that a large proportion of defects quickly releases trapped charge carriers. These results could help to further improve the properties of perovskite solar cells.

  • Portrait Annette Pietzsch: Researching fundamental phenomena of our world
    Portrait
    07.10.2021
    Portrait Annette Pietzsch: Researching fundamental phenomena of our world
    Annette Pietzsch has many jobs: the physicist develops instruments for BESSY II that researchers can use to observe how molecules interact with each other. She mostly prefers to use the instruments to do her own research. This is what brought her from Sweden to HZB ten years ago.
  • A sharp look into tiny ferroelectric crystals
    Science Highlight
    06.10.2021
    A sharp look into tiny ferroelectric crystals
    What happens to ferroelectric materials when their dimensions are greatly reduced? A team of researchers at HZB has now been able to show how this question can be answered in a detailed way.

  • Beam diagnostics for future laser wakefield accelerators
    Science Highlight
    30.09.2021
    Beam diagnostics for future laser wakefield accelerators
    For decades, particle accelerators have been getting bigger and bigger. In the meantime, ring accelerators with circumferences of many kilometres have reached a practical limit. Linear accelerators in the GHz range also require very long construction lengths. For some years now, however, an alternative is explored: "tabletop particle accelerators" based on the laser excitation of charge waves in plasmas (laser wakefield). Such compact particle accelerators would be particularly interesting for future accelerator-driven light sources, but are also being investigated for high-energy physics. A team from Helmholtz-Zentrum Berlin (HZB) and the Physikalisch-Technische Bundesanstalt (PTB) has developed a method to precisely measure the cross-section of electron bunches accelerated in this way.  This brings applications of these new accelerator technologies for medicine and research closer.

  • New world record in materials research - X-ray microscopy with 1000 tomograms per second
    Science Highlight
    27.09.2021
    New world record in materials research - X-ray microscopy with 1000 tomograms per second
    Tomoscopy is an imaging method in which three-dimensional images of the inside of materials are calculated in rapid succession. Now a team led by HZB physicist Francisco García Moreno has achieved a new world record at the TOMCAT beamline of the Swiss Light Source at the Paul Scherrer Institute: with 1000 tomograms per second, it is now possible to non-destructively document very fast processes and developments in materials on the micrometre scale, such as the burning of a sparkler or the foaming of a metal alloy for the production of stable lightweight materials. 

  • Surface analysis at BESSY II: sharper insights into thin-film systems
    Science Highlight
    16.09.2021
    Surface analysis at BESSY II: sharper insights into thin-film systems

    Interfaces in semiconductor components or solar cells play a crucial role for functionality. Nevertheless, until now it has often been difficult to investigate adjacent thin films separately using spectroscopic methods. An HZB team at BESSY II has combined two different spectroscopic methods and used a model system to demonstrate how well they can be distinguished.

  • Disorder brings out quantum physical talents
    Science Highlight
    01.09.2021
    Disorder brings out quantum physical talents
    Quantum effects are most noticeable at extremely low temperatures, which limits their usefulness for technical applications. Thin films of MnSb2Te4, however, show new talents due to a small excess of manganese. Apparently, the resulting disorder provides spectacular properties: The material proves to be a topological insulator and is ferromagnetic up to comparatively high temperatures of 50 Kelvin, measurements at BESSY II show.  This makes this class of material suitable for quantum bits, but also for spintronics in general or applications in high-precision metrology.

  • On the trail of lithium dendrites: How destructive formations develop in batteries
    Science Highlight
    01.09.2021
    On the trail of lithium dendrites: How destructive formations develop in batteries
    Tiny formations inside lithium batteries can severely limit the operating life of an energy storage device. A research team at the Helmholtz-Zentrum Berlin (HZB) has now investigated the process behind these formations in greater detail. Their results provide anchor points for the future development of longer-lasting and safer lithium batteries.
  • Review: X-ray scattering methods with synchrotron radiation
    News
    18.08.2021
    Review: X-ray scattering methods with synchrotron radiation
    Synchrotron light sources provide brilliant light with a focus on the X-ray region and have enormously expanded the possibilities for characterising materials. In the Reviews of Modern Physics, an international team now gives an overview of elastic and inelastic X-ray scattering processes, explains the theoretical background and sheds light on what insights these methods provide in physics, chemistry as well as bio- and energy related themes.

  • Green hydrogen: Why do certain catalysts improve in operation?
    Science Highlight
    09.08.2021
    Green hydrogen: Why do certain catalysts improve in operation?
    Crystalline cobalt arsenide is a catalyst that generates oxygen during electrolytic water splitting in the production of hydrogen. The material is considered to be a model system for an important group of catalysts whose performance increases under certain conditions in the course of electrolysis. Now a HZB-team headed by Marcel Risch has observed at BESSY II how two simultaneous mechanisms are responsible for this. The catalytic activity of the individual catalysis centres decreases in the course of electrolysis, but at the same time the morphology of the catalyst layer also changes. Under favourable conditions, considerably more catalysis centres come into contact with the electrolyte as a result, so that the overall performance of the catalyst increases.

  • When vibrations increase on cooling: Anti-freezing observed
    Science Highlight
    04.08.2021
    When vibrations increase on cooling: Anti-freezing observed
    An international team has observed an amazing phenomenon in a nickel oxide material during cooling: Instead of freezing, certain fluctuations actually increase as the temperature drops. Nickel oxide is a model system that is structurally similar to high-temperature superconductors. The experiment shows once again that the behaviour of this class of materials still holds surprises.

  • Water as a metal - detected at BESSY II
    Science Highlight
    28.07.2021
    Water as a metal - detected at BESSY II
    Under normal conditions, pure water is an almost perfect insulator. Water only develops metallic properties under extreme pressure, such as exists deep inside of large planets. Now, an international collaboration has used a completely different approach to produce metallic water and documented the phase transition at BESSY II. The study is published now in Nature.

  • Lead-free perovskite solar cells - How fluoride additives improve quality
    Science Highlight
    26.07.2021
    Lead-free perovskite solar cells - How fluoride additives improve quality
    Tin halide perovskites are currently considered the best alternative to their lead-containing counterparts, which are, however, still significantly less efficient and stable. Now, a team led by Prof. Antonio Abate from HZB has analysed the chemical processes in the perovskite precursor solution and the fluoride compounds in detail. Using a clever combination of measurement methods at BESSY II and with NMR at the Humboldt-University Berlin, they were able to show that fluoride prevents the oxidation of tin and leads to a more homogeneous film formation with fewer defects, increasing the quality of the semiconductor layer.

  • Future information technologies: Topological materials for ultrafast spintronics
    Science Highlight
    16.07.2021
    Future information technologies: Topological materials for ultrafast spintronics
    A team led by HZB physicist Dr. Jaime Sánchez-Barriga has gained new insights into the ultrafast response of topological states of matter to femtosecond laser excitation. Using time- and spin-resolved methods at BESSY II, the physicists explored how, after optical excitation, the complex interplay in the behavior of excited electrons in the bulk and on the surface results in unusual spin dynamics. The work is an important step on the way to spintronic devices based on topological materials for ultrafast information processing.

  • Solar hydrogen for Antarctica - study shows advantages of thermally coupled approach
    Science Highlight
    02.07.2021
    Solar hydrogen for Antarctica - study shows advantages of thermally coupled approach
    A team from the Helmholtz-Zentrum Berlin, Ulm University, and Heidelberg University has now investigated how hydrogen can be produced at the South Pole using sunlight, and which method is the most promising. Their conclusion: in extremely cold regions, it can be considerably more efficient to attach the PV modules directly to the electrolyser, i.e. to thermally couple them. This is because the waste heat from the PV modules increases the efficiency of electrolysis in this environment. The results of this study, which has now been published in Energy & Environmental Science, are also relevant for other cold regions on Earth, such as Alaska, Canada, and high mountain regions, for example. In these places, solar hydrogen could replace fossil fuels such as oil and petrol.

  • Synchrotrons accelerate corona research
    News
    29.06.2021
    Synchrotrons accelerate corona research
    Information by the German Committee Research with Synchrotron Radiation (KFS).

    Synchrotron light sources were originally built to study particles. Today, they are even used in the fight against COVID-19. The projects are as diverse as the fields of the synchrotron users, who come from universities, research institutions and companies like BioNTech.

  • Perovskite Solar Cells: Insights into early stages of structure formation
    Science Highlight
    18.06.2021
    Perovskite Solar Cells: Insights into early stages of structure formation
    Using small-angle scattering at the PTB X-ray beamline of BESSY II, an HZB team was able to experimentally investigate the colloidal chemistry of perovskite precursor solutions used for solar cell production. The results contribute to the targeted and systematic optimization of the manufacturing process and quality of these exciting semiconductor materials.

  • How quantum dots can "talk" to each other
    Science Highlight
    03.06.2021
    How quantum dots can "talk" to each other

    A group at HZB has worked out theoretically how the communication between two quantum dots can be influenced with light.  The team led by Annika Bande also shows ways to control the transfer of information or energy from one quantum dot to another. To this end, the researchers calculated the electronic structure of two nanocrystals, which act as quantum dots. With the results, the movement of electrons in quantum dots can be simulated in real time.

  • Renske van der Veen heads new department "Atomic Dynamics in Light-Energy Conversion"
    News
    02.06.2021
    Renske van der Veen heads new department "Atomic Dynamics in Light-Energy Conversion"
    From June 2021, Dr. Renske van der Veen is setting up a new research group at HZB. The chemist is an expert in time-resolved X-ray spectroscopy and electron microscopy and studies catalytic processes that enable the conversion of solar energy into chemical energy.

  • Perovskite solar cells: Hydrogen bonds measured
    Science Highlight
    26.05.2021
    Perovskite solar cells: Hydrogen bonds measured
    The evaluation of X-ray measurements on methylammonium perovskite semiconductors now shows what role hydrogen bonds play in these materials. In addition, the HZB team showed that radiation damage by soft X-rays to this sensitive class of materials occurs even faster than often expected. Both results provide important information for perovskites materials research for solar cells.

  • Direct observation of the ad- and desorption of guest atoms into a mesoporous host
    Science Highlight
    21.04.2021
    Direct observation of the ad- and desorption of guest atoms into a mesoporous host
    Battery electrodes, storage devices for gases, and some catalyst materials have tiny functional pores that can accommodate atoms, ions, and molecules. How these guest atoms are absorbed into or released from the pores is crucial to understanding the porous materials' functionality. However, usually these processes can only be observed indirectly. A team from the Helmholtz Zentrum Berlin (HZB) has employed two experimental approaches using the ASAXS instrument at the PTB X-ray beamline of the HZB BESSY II synchrotron to directly observe the adsorption process of atoms in a mesoporous model system. The work lays the foundations for new insights into these kinds of energy materials.

  • Green hydrogen: "Rust" as a photoanode and its limits
    Science Highlight
    19.04.2021
    Green hydrogen: "Rust" as a photoanode and its limits
    Metal oxides such as rust are intriguing photoelectrode materials for the production of green hydrogen with sunlight. They are cheap and abundant, but in spite of decades of research, progress has been limited. A team at HZB, together with partners from Ben Gurion University and the Technion, Israel, has now analysed the optoelectronic properties of rust (haematite) and other metal oxides in unprecedented detail. Their results show that the maximum achievable efficiency of haematite electrodes is significantly lower than previously assumed. The study demonstrates ways to assess new photoelectrode materials more realistically.

  • X-ray lightsource at DESY identifies promising candidates for COVID drugs
    Science Highlight
    06.04.2021
    X-ray lightsource at DESY identifies promising candidates for COVID drugs
    At DESY's high-brilliance X-ray light source PETRA III, a team from more than 30 research institutions has identified several candidates for active substances against the coronavirus SARS-CoV-2. They bind to an important protein of the virus and could thus be the basis for a drug against Covid-19. The MX team from HZB examined part of the measurement data with special analysis algorithms in order to identify suitable active substances. The study has now been published in the renowned journal Science.

  • New insights into the structure of organic-inorganic hybrid perovskites
    Science Highlight
    22.03.2021
    New insights into the structure of organic-inorganic hybrid perovskites
    In photovoltaics, organic-inorganic hybrid perovskites have made a rapid career. But many questions about the crystalline structure of this surprisingly complex class of materials remain unanswered. Now, a team at HZB has used four-dimensional modelling to interpret structural data of methylammonium lead bromide (MAPbBr3), identifying incommensurable superstructures and modulations of the predominant structure. The study is published in the ACS Journal of Physical Chemistry Letters and was selected by the editors as an Editor's Choice.

  • Solar cells: Losses made visible on the nanoscale
    Science Highlight
    17.03.2021
    Solar cells: Losses made visible on the nanoscale
    Solar cells made of crystalline silicon achieve peak efficiencies, especially in combination with selective contacts made of amorphous silicon (a-Si:H). However, their efficiency is limited by losses in these contact layers. Now, for the first time, a team at Helmholtz-Zentrum Berlin (HZB) and the University of Utah, USA, has experimentally shown how such contact layers generate loss currents on the nanometre scale and what their physical origin is. Using a conductive atomic force microscope, they scanned the solar cell surfaces in ultra-high vacuum and detected tiny, nanometre-sized channels for the detrimental dark currents, which are due to disorder in the a-Si:H layer.

  • Instrument at BESSY II shows how light activates MoS2 layers to become catalysts
    Science Highlight
    05.03.2021
    Instrument at BESSY II shows how light activates MoS2 layers to become catalysts
    Thin films of molybdenum and sulfur belong to a class of materials that can be considered for use as photocatalysts. Inexpensive catalysts such as these are needed to produce hydrogen as a fuel using solar energy. However, they are still not very efficient as catalysts. A new instrument at the Helmholtz-Berlin Zentrum’s BESSY II now shows how a light pulse alters the surface properties of the thin film and activates the material as a catalyst.

  • Accelerator physics: Experiment reveals new options for synchrotron light sources
    Science Highlight
    24.02.2021
    Accelerator physics: Experiment reveals new options for synchrotron light sources
    An international team has shown through a sensational experiment how diverse the possibilities for employing synchrotron light sources are. Accelerator experts from the Helmholtz-Zentrum Berlin (HZB), the German federal metrology institute Physikalisch-Technische Bundesanstalt (PTB), and Tsinghua University in Beijing have used a laser to manipulate electron bunches at PTB's Metrology Light Source so that they emitted intense light pulses having a laser-like character. Using this method, specialised synchrotron radiation sources would potentially be able to fill a gap in the arsenal of available light sources and offer a prototype for industrial applications. The work was published on 24 February 2021 in the leading scientific publication Nature.

  • The perfect recipe for efficient perovskite solar cells
    Science Highlight
    22.02.2021
    The perfect recipe for efficient perovskite solar cells
    A long-cherished dream of materials researchers is a solar cell that converts sunlight into electrical energy as efficiently as silicon, but that can be easily and inexpensively fabricated from abundant materials. Scientists at the Helmholtz-Zentrum Berlin have now come a step closer to achieving this. They have improved a process for vertically depositing a solution made from an inexpensive perovskite solute onto a moving substrate below. Not only have they discovered the crucial role played by one of the solvents used, but they have also taken a closer look at the aging and storage properties of the solution.

  • An efficient tool to link X-ray experiments and ab initio theory
    Science Highlight
    28.01.2021
    An efficient tool to link X-ray experiments and ab initio theory
    The electronic structure of complex molecules and their chemical reactivity can be assessed by the method of resonant inelastic X-ray scattering (RIXS) at BESSY II. However, the evaluation of RIXS data has so far required very long computing times. A team at BESSY II has now developed a new simulation method that greatly accelerates this evaluation. The results can even be calculated during the experiment. Guest users could use the procedure like a black box.

  • Solar hydrogen: Photoanodes made of α-SnWO4 promise high efficiencies
    Science Highlight
    26.01.2021
    Solar hydrogen: Photoanodes made of α-SnWO4 promise high efficiencies
    Photoanodes made of metal oxides are considered to be a viable solution for the production of hydrogen with sunlight. α-SnWO4 has optimal electronic properties for photoelectrochemical water splitting with sunlight, but corrodes easily. Protective layers of nickel oxide prevent corrosion, but reduce the photovoltage and limit the efficiency. Now a team at HZB has investigated at BESSY II what happens at the interface between the photoanode and the protective layer. Combined with theoretical methods, the measurement data reveal the presence of an oxide layer that impairs the efficiency of the photoanode.


  • Accelerator Physics: HF-Couplers for bERLinPro prove resilient
    News
    07.01.2021
    Accelerator Physics: HF-Couplers for bERLinPro prove resilient
    In synchrotron light sources, an electron accelerator brings electron bunches to almost the speed of light so that they can emit the special "synchrotron light". The electron bunches get their enormous energy and their special shape from a standing electromagnetic alternating field in so-called cavities. With high electron currents, as required in the bERLinPro project, the power needed for the stable excitation of this high-frequency alternating field is enormous. The coupling of this high power is achieved with special antennas, so-called couplers, and is considered a great scientific and technical challenge. Now, a first measurement campaign with optimised couplers at bERLinPro shows that the goal can be achieved.

  • Perovskite/silicon tandem solar cells on the threshold of 30% efficiency
    Science Highlight
    11.12.2020
    Perovskite/silicon tandem solar cells on the threshold of 30% efficiency
    An HZB team has published a report in the journal Science on the development of its current world record of 29.15% efficiency for a tandem solar cell made of perovskite and silicon. The tandem cell provided stable performance for 300 hours – even without encapsulation. To accomplish this, the group headed by Prof. Steve Albrecht investigated physical processes at the interfaces to improve the transport of the charge carriers.

  • Perovskite Solar Cells: paving the way for rational ink design for industrial-scale manufacturing
    Science Highlight
    27.11.2020
    Perovskite Solar Cells: paving the way for rational ink design for industrial-scale manufacturing
    For the production of high-quality metal-halide perovskite thin-films for large area photovoltaic modules often optimized inks are used which contain a mixture of solvents. An HZB team at BESSY II has now analysed the crystallisation processes within such mixtures. A model has also been developed to assess the kinetics of the crystallisation processes for different solvent mixtures. The results are of high importance for the further development of perovskite inks for industrial-scale deposition processes of these semiconductors.

  • Solar cells: Mapping the landscape of Caesium based inorganic halide perovskites
    Science Highlight
    16.11.2020
    Solar cells: Mapping the landscape of Caesium based inorganic halide perovskites
    Scientists at HZB have printed and explored different compositions of caesium based halide perovskites (CsPb(BrxI1−x)3 (0 ≤ x ≤ 1)). In a temperature range between room temperature and 300 Celsius, they observe structural phase transitions influencing the electronic properties. The study provides a quick and easy method to assess new compositions of perovskite materials in order to identify candidates for applications in thin film solar cells and optoelectronic devices.

  • Order in the disorder: density fluctuations in amorphous silicon discovered
    Science Highlight
    29.10.2020
    Order in the disorder: density fluctuations in amorphous silicon discovered
    For the first time, a team at HZB has identified the atomic substructure of amorphous silicon with a resolution of 0.8 nanometres using X-ray and neutron scattering at BESSY II and BER II. Such a-Si:H thin films have been used for decades in solar cells, TFT displays, and detectors. The results show that three different phases form within the amorphous matrix, which dramatically influences the quality and lifetime of the semiconductor layer. The study was selected for the cover of the actual issue of Physical Review Letters.

  • Modelling shows which quantum systems are suitable for quantum simulations
    Science Highlight
    27.10.2020
    Modelling shows which quantum systems are suitable for quantum simulations
    A joint research group led by Prof. Jens Eisert of Freie Universität Berlin and Helmholtz-Zentrum Berlin (HZB) has shown a way to simulate the quantum physical properties of complex solid state systems. This is done with the help of complex solid state systems that can be studied experimentally. The study was published in the renowned journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).
  • Solar hydrogen: Let’s consider the stability of photoelectrodes
    Science Highlight
    26.10.2020
    Solar hydrogen: Let’s consider the stability of photoelectrodes

    As part of an international collaboration, a team at the HZB has examined the corrosion processes of high-quality BiVO4 photoelectrodes using different state-of-the-art characterisation methods. The result is the first operando stability study of high-purity BiVO4 photoanodes during the photoelectrochemical oxygen evolution reaction (OER). This work shows how the stability of photoelectrodes and catalysts can be compared and enhanced in the future.

  • Nanopatterns of proteins detected by cryo-electron microscopy
    Science Highlight
    15.10.2020
    Nanopatterns of proteins detected by cryo-electron microscopy
    A team from Helmholtz-Zentrum Berlin (HZB) used cryo electron microscopy to detect regular, two-dimensional structures in the form of Pascal triangles in a shock frozen protein material.  The samples have been synthesized by a Chinese research group. The method of cryo electron microscopy has the potential for new insights into energy materials as well.
  • Perovskite materials: Neutrons show twinning in halide perovskites
    Science Highlight
    12.10.2020
    Perovskite materials: Neutrons show twinning in halide perovskites
    Solar cells based on hybrid halide perovskites achieve high efficiencies. These mixed organic-inorganic semiconductors are usually produced as thin films of microcrystals. An investigation with the Laue camera at the neutron source BER II could now clarify that twinning occurs during crystallisation even at room temperature. This insight is helpful for optimising production processes of halide perovskites. 

  • Upconversion of photons at low light intensities – the key to new applications in energy and bioengineering
    Science Highlight
    04.09.2020
    Upconversion of photons at low light intensities – the key to new applications in energy and bioengineering
    The region of the spectrum that can be utilised for producing electrical energy can be considerably extended by converting low-energy (longer wavelength) photons into high-energy (shorter wavelength) photons. But so far, this has only been possible at high intensities of light. Now for the first time, scientists from the Helmholtz-Zentrum Berlin (HZB) and the Federal Institute for Materials Research and Testing (BAM) have been able to produce a usable effect from relatively weak light by combining certain nanoparticles with what is known as a meta-surface. This paves the way for future applications in photovoltaics, for the detection of biological substances, and for electrical-field sensors.
  • Molecular architecture: New class of materials for tomorrow's energy storage
    Science Highlight
    26.08.2020
    Molecular architecture: New class of materials for tomorrow's energy storage
    Researchers at the Technische Universität Berlin (TUB) have created a new family of semiconductors, the properties of which were investigated by the Helmholtz-Zentrum Berlin (HZB). The researchers christened the first member “TUB75”. The material belongs to the class called metal-organic frameworks, or MOFs for short, and could open up new opportunities for energy storage. The work was published in Advanced Materials.
  • Mathematical tool helps calculate properties of quantum materials more quickly
    Science Highlight
    14.08.2020
    Mathematical tool helps calculate properties of quantum materials more quickly
    Many quantum materials have been nearly impossible to simulate mathematically because the computing time required is too long. Now a joint research group at Freie Universität Berlin and the Helmholtz-Zentrum Berlin (HZB) has demonstrated a way to considerably reduce the computing time. This could accelerate the development of materials for energy-efficient IT technologies of the future.

  • Hope for better batteries – researchers follow the charging and discharging of silicon electrodes live
    Science Highlight
    29.07.2020
    Hope for better batteries – researchers follow the charging and discharging of silicon electrodes live

    Using silicon as a material for electrodes in lithium-ion batteries promises a significant increase in battery amp-hour capacity.The shortcoming of this material is that it is easily damaged by the stress caused by charging and discharging.Scientists at the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) have now succeeded for the first time in observing this process directly on crystalline silicon electrodes in detail.Operando experiments using the BESSY II synchrotronprovided new insights into how fractures occur in silicon – and also how the material can nevertheless be utilised advantageously.

  • New substance library to accelerate the search for active compounds
    Science Highlight
    13.07.2020
    New substance library to accelerate the search for active compounds
    In order to accelerate the systematic development of drugs, the MX team at the Helmholtz-Zentrum Berlin (HZB) and the Drug Design Group at the University of Marburg have established a new substance library. It consists of 1103 organic molecules that could be used as building blocks for new drugs. The MX team has now validated this library in collaboration with the FragMAX group at MAX IV. The substance library of the HZB is available for research worldwide and also plays a role in the search for substances active against SARS-CoV-2.

  • Robust high-performance data storage through magnetic anisotropy
    Science Highlight
    10.07.2020
    Robust high-performance data storage through magnetic anisotropy
    The latest generation of magnetic hard drives is made of magnetic thin films, which are invar materials. They allow extremely robust and high data storage density by local heating of ultrasmall nano-domains with a laser, so called heat assisted magnetic recording or HAMR. The volume in such invar materials hardly expands despite heating. A technologically relevant material for such HAMR data memories are thin films of iron-platinum nanograins. An international team led by the joint research group of Prof. Dr. Matias Bargheer at HZB and the University of Potsdam has now observed experimentally for the first time how a special spin-lattice interaction in these iron-platinum thin films cancels out the thermal expansion of the crystal lattice. The study has been published in Science Advances.

  • Printed perovskite LEDs – an innovative technique towards a new standard process of electronics manufacturing
    Science Highlight
    12.06.2020
    Printed perovskite LEDs – an innovative technique towards a new standard process of electronics manufacturing

    A team of researchers from the Helmholtz-Zentrum Berlin (HZB) and Humboldt-Universität zu Berlin has succeeded for the first time in producing light-emitting diodes (LEDs) from a hybrid perovskite semiconductor material using inkjet printing.This opens the door to broad application of these materials in manufacturing many different kinds of electronic components.The scientists achieved the breakthrough with the help of a trick: "inoculating" (or seeding) the surface with specific crystals.

  • BESSY II: Experiment shows for the first time in detail how electrolytes become metallic
    Science Highlight
    05.06.2020
    BESSY II: Experiment shows for the first time in detail how electrolytes become metallic
    An international team has developed a sophisticated experimental technique at BESSY II to observe the formation of a metallic conduction band in electrolytes. To accomplish this, the team first prepared cryogenic solutions of liquid ammonia containing different concentrations of alkali metals. The colour of the solutions changes with concentration from blue to golden as the individual atoms of metal in solution transition to a metallic compound. The team then examined these liquid jets using soft X-rays at BESSY II and subsequently has been able to analyse this process in detail from the data they acquired combined with theoretical predictions. The work has been published in Science and appears even on the cover.
  • Catalysts: Efficient hydrogen production via structure
    Science Highlight
    02.06.2020
    Catalysts: Efficient hydrogen production via structure

    Regeneratively produced hydrogen is considered the ecological raw material of the future. In order to produce it efficiently by electrolysis of water, researchers today also investigate perovskite oxides. The Journal of Physics: Energy invited Dr. Marcel Risch from the Helmholtz-Zentrum Berlin (HZB) to outline the current state of research.

  • On the road to non-toxic and stable perovskite solar cells
    Science Highlight
    11.05.2020
    On the road to non-toxic and stable perovskite solar cells
    The promising halide perovskite materials for solar energy conversion show high efficiencies, but this comes at a cost: The best perovskite materials incorporate toxic lead which poses a hazard to the environment. To replace lead by less toxic elements is not easy since lead-free perovskites show lower stability and poor efficiencies. Now, an international collaboration has engineered a new hybrid perovskite material with promising efficiency and stability.
  • Future information technologies: 3D Quantum Spin Liquid revealed
    Science Highlight
    11.05.2020
    Future information technologies: 3D Quantum Spin Liquid revealed
    Quantum Spin Liquids are candidates for potential use in future information technologies. So far, Quantum Spin Liquids have usually only been found in one or two dimensional magnetic systems only. Now an international team led by HZB scientists has investigated crystals of PbCuTe2O6 with neutron experiments at ISIS, NIST and ILL. They found spin liquid behaviour in 3D, due to a so called hyper hyperkagome lattice. The experimental data fit extremely well to theoretical simulations also done at HZB.
  • Tandem solar cell world record: New branch in the NREL chart
    Science Highlight
    14.04.2020
    Tandem solar cell world record: New branch in the NREL chart
    A special branch in the famous NREL-chart for solar cell world records refers to a newly developed tandem solar cell by HZB teams. The world-record cell combines the semiconductors perovskite and CIGS to a monolithic "two-terminal" tandem cell. Due to the thin-film technologies used, such tandem cells survive much longer in space and can even be produced on flexible films. The new tandem cell achieves a certified efficiency of 24.16 percent.
  • Condensed Matter Physics: Long-standing prediction of quantum physics experimentally proven
    Science Highlight
    06.04.2020
    Condensed Matter Physics: Long-standing prediction of quantum physics experimentally proven
    90 years ago, the physicist Hans Bethe postulated that unusual patterns, so-called Bethe strings, appear in certain magnetic solids. Now an international team has succeeded in experimentally detecting such Bethe strings for the first time. They used neutron scattering experiments at various neutron facilities including the unique high-field magnet of BER II* at HZB. The experimental data are in excellent agreement with the theoretical prediction of Bethe and prove once again the power of quantum physics.
  • BESSY II: Ultra-fast switching of helicity of circularly polarized light pulses
    Science Highlight
    01.04.2020
    BESSY II: Ultra-fast switching of helicity of circularly polarized light pulses
    At the BESSY II storage ring, a joint team of accelerator physicists, undulator experts and experimenters has shown how the helicity of circularly polarized synchrotron radiation can be switched faster - up to a million times faster than before. They used an elliptical double-undulator developed at HZB and operated the storage ring in the so-called two-orbit mode. This is a special mode of operation that was only recently developed at BESSY II and provides the basis for fast switching. The ultra-fast change of light helicity is particularly interesting to observe processes in magnetic materials and has long been expected by a large user community.
  • Fast and furious: New class of 2D materials stores electrical energy
    Science Highlight
    02.03.2020
    Fast and furious: New class of 2D materials stores electrical energy
    Two dimensional titanium carbides, so-called MXenes, are being discussed as candidates for the rapid storage of electrical energy. Like a battery,MXenes can store large amounts of electrical energy through electrochemical reactions- but unlike batteries,can be charged and discharged in a matter of seconds. In collaboration with Drexel University, a team at HZB showed that the intercalation of urea molecules between the MXene layers can increase the capacity of such "pseudo-capacitors" by more than 50 percent. At BESSY II they have analysed how changes of the MXene surface chemistry after urea intercalation are responsible for this.
  • New detector accelerates protein crystallography
    News
    17.02.2020
    New detector accelerates protein crystallography

    Last week a new detector was installed at one of the three MX beamlines at HZB. Compared to the old detector the new one is better, faster and more sensitive. It allows to acquire complete data sets of complex proteins within a very short time.

  • X-ray microscopy at BESSY II: Nanoparticles can change cells
    Science Highlight
    12.02.2020
    X-ray microscopy at BESSY II: Nanoparticles can change cells
    Nanoparticles easily enter into cells. New insights about how they are distributed and what they do there are shown for the first time by high-resolution 3D microscopy images from the lightsources BESSY II and ALBA. For example, certain nanoparticles accumulate preferentially in certain organelles of the cell. This can increase the energy costs in the cell. "The cell looks like it has just run a marathon, apparently, the cell requires energy to absorb such nanoparticles" says lead author James McNally.
  • Not everything is ferromagnetic in high magnetic fields
    Science Highlight
    10.02.2020
    Not everything is ferromagnetic in high magnetic fields
    High magnetic fields have a potential to modify the microscopic arrangement of magnetic moments because they overcome interactions existing in zero field. Usually, high fields exceeding a certain critical value force the moments to align in the same direction as the field leading to ferromagnetic arrangement. However, a recent study showed that this is not always the case. The experiments took place at the high-field magnet at HZB's neutron source BER II, which generates a constant magnetic field of up to 26 Tesla. This is about 500,000 times stronger than the Earth's magnetic field. Further experiments with pulsed magnetic fields up to 45 Tesla were performed at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). 
  • Battery research: Using neutrons and X-rays to analyse the ageing of lithium batteries
    Science Highlight
    07.02.2020
    Battery research: Using neutrons and X-rays to analyse the ageing of lithium batteries
    An international team has used neutron and X-ray tomography to investigate the dynamic processes that lead to capacity degradation at the electrodes in lithium batteries. Using a new mathematical method, it was possible to virtually unwind electrodes that had been wound into the form of a compact cylinder, and thus actually observe the processes on the surfaces of the electrodes. The study was published in Nature Communications.
  • Perovskite solar cells: International consensus on ageing measurement protocols
    Science Highlight
    31.01.2020
    Perovskite solar cells: International consensus on ageing measurement protocols
    Experts from 51 research institutions have now agreed on the procedures for measuring the stability of perovskite solar cells and assessing their quality. The consensus statement was published in Nature Energy and is considered a milestone for the further development of this new type of solar cell on its way to industrial application.
  • World Record: Efficiency of perovskite silicon tandem solar cell jumps to 29.15 per cent
    Science Highlight
    29.01.2020
    World Record: Efficiency of perovskite silicon tandem solar cell jumps to 29.15 per cent
    In the race for ever higher efficiency levels, an HZB development team has once again pulled ahead. The groups of Steve Albrecht and Bernd Stannowski have developed a tandem solar cell made of the semiconductors perovskite and silicon, that converts 29.15 per cent of the incident light into electrical energy. This value has been officially certified by the CalLab of the Fraunhofer Institute for Solar Energy Systems (ISE) and means that surpassing the 30 per cent efficiency mark is now within reach.
  • Plants absorb lead from perovskite solar cells more than expected
    Science Highlight
    21.01.2020
    Plants absorb lead from perovskite solar cells more than expected
    Lead from metal-organic perovskite compounds can be absorbed particularly easily by plants. The bioavailability is significantly higher than that of lead from inorganic compounds as found in batteries. This is shown in a study by HZB researcher Antonio Abate with partners in China and Italy, published in Nature communications.
  • Topological materials for information technology offer lossless transmission of signals
    Science Highlight
    18.12.2019
    Topological materials for information technology offer lossless transmission of signals
    New experiments with magnetically doped topological insulators at BESSY II have revealed possible ways of lossless signal transmission that involve a surprising self-organisation phenomenon. In the future, it might be possible to develop materials that display this phenomenon at room temperature and can be used as processing units in a quantum computer, for example. The study has been published in the renowned journal Nature.
  • Perovskite solar cells: Possible aspects of high efficiency uncovered
    Science Highlight
    13.11.2019
    Perovskite solar cells: Possible aspects of high efficiency uncovered
    Using crystallographic analyses at the Diamond Light Source (DLS) synchrotron in the United Kingdom, an HZB team has demonstrated that hybrid halide perovskites crystallise without inversion centre. Interactions between the organic molecules and adjacent iodine atoms can lead to the formation of ferroelectric domains, which, indirectly, can result in higher solar-cell efficiencies. The formation of these ferroelectric domains cannot occur in purely inorganic perovskites.
  • Dynamic pattern of Skyrmions observed
    Science Highlight
    15.10.2019
    Dynamic pattern of Skyrmions observed
    Tiny magnetic vortices known as skyrmions form in certain magnetic materials, such as Cu2OSeO3. These skyrmions can be controlled by low-level electrical currents – which could facilitate more energy-efficient data processing. Now a team has succeeded in developing a new technique at the VEKMAG station of BESSY II for precisely measuring these vortices and observing their three different predicted characteristic oscillation modes (Eigen modes).
  • World record for tandem perovskite-CIGS solar cell
    Science Highlight
    09.09.2019
    World record for tandem perovskite-CIGS solar cell
    A team headed by Prof. Steve Albrecht from the HZB will present a new world-record tandem solar cell at EU PVSEC, the world's largest international photovoltaic and solar energy conference and exhibition, in Marseille, France on September 11, 2019. This tandem solar cell combines the semiconducting materials perovskite and CIGS and achieves a certified efficiency of 23.26 per cent. One reason for this success lies in the cell’s intermediate layer of organic molecules: they self-organise to cover even rough semiconductor surfaces. Two patents have been filed for these layers.
  • Nanoparticles in lithium-sulphur batteries detected with neutron experiment
    Science Highlight
    06.09.2019
    Nanoparticles in lithium-sulphur batteries detected with neutron experiment
    An HZB team has for the first time precisely analysed how nanoparticles of lithium sulphide and sulphur precipitate onto battery electrodes during the course of the charging cycle. The results can help increase the service life of lithium-sulphur batteries.
  • Save time using maths: analytical tool designs corkscrew-shaped nano-antennae
    Science Highlight
    23.08.2019
    Save time using maths: analytical tool designs corkscrew-shaped nano-antennae
    For the first time, an HZB team has derived analytically how corkscrew-shaped nano-antennas interact with light. The mathematical tool can be used to calculate the geometry that a nano-antenna must have for specific applications in sensor technology or information technology.
  • World record in tomography: Watching how metal foam forms
    Science Highlight
    21.08.2019
    World record in tomography: Watching how metal foam forms
    An international research team at the Swiss Light Source (SLS) has set a new tomography world record using a rotary sample table developed at the HZB. With 208 three-dimensional tomographic X-ray images per second, they were able to document the dynamic processes involved in the foaming of liquid aluminium. The method is presented in the journal Nature Communications.
  • FOCUS TOPIC: Catching more light in solar cells
    Portrait
    05.08.2019
    FOCUS TOPIC: Catching more light in solar cells
    Christiane Becker uses microscopic structures to increase the amount of light captured in solar cells and is currently scaling up the technology for industrial application. “On top of everything else, there’s this spirit at HZB that we are working on the renewable energies of the future, and that is incredibly inspiring,” she relates in portrait.
  • FOCUS TOPIC: Using BESSY II to combat plastic waste
    News
    30.07.2019
    FOCUS TOPIC: Using BESSY II to combat plastic waste
    Plastics are excellent materials: extremely versatile and almost eternally durable. But this is also exactly the problem, because after only about 100 years of producing plastics, plastic particles are now found everywhere – in groundwater, in the oceans, in the air, and in the food chain.

  • Accelerator physics: alternative material investigated for superconducting radio-frequency cavity resonators
    Science Highlight
    15.07.2019
    Accelerator physics: alternative material investigated for superconducting radio-frequency cavity resonators
    In modern synchrotron sources and free-electron lasers, superconducting radio-frequency cavity resonators are able to supply electron bunches with extremely high energy. These resonators are currently constructed of pure niobium. Now an international collaboration has investigated the potential advantages a niobium-tin coating might offer in comparison to pure niobium.
  • Charge transfer within transition-metal dyes analysed
    Science Highlight
    09.07.2019
    Charge transfer within transition-metal dyes analysed
    Transition-metal complexes in dye-based solar cells are responsible for converting light into electrical energy. A model of spatial charge separation within the molecule has been used to describe this conversion. However, an analysis at BESSY II shows that this description of the process is too simple. For the first time, a team there has investigated the fundamental photochemical processes around the metal atom and its ligands. The study has now been published in “Angewandte Chemie, international Edition” and is displayed on the cover.
  • Utrafast magnetism: electron-phonon interactions examined at BESSY II
    Science Highlight
    28.06.2019
    Utrafast magnetism: electron-phonon interactions examined at BESSY II
    How fast can a magnet switch its orientation and what are the microscopic mechanisms at play ? These questions are of first importance for the development of data storage and computer chips. Now, an HZB team at BESSY II has for the first time been able to experimentally assess the principal microscopic process of ultra-fast magnetism. The methodology developed for this purpose can also be used to investigate interactions between spins and lattice oscillations in graphene, superconductors or other (quantum) materials.
  • Organic electronics: a new semiconductor in the carbon-nitride family
    Science Highlight
    05.06.2019
    Organic electronics: a new semiconductor in the carbon-nitride family
    Teams from Humboldt-Universität and the Helmholtz-Zentrum Berlin have explored a new material in the carbon-nitride family. Triazine-based graphitic carbon nitride (TGCN) is a semiconductor that should be highly suitable for applications in optoelectronics. Its structure is two-dimensional and reminiscent of graphene. Unlike graphene, however, the conductivity in the direction perpendicular to its 2D planes is 65 times higher than along the planes themselves.
  • Development of a miniaturised EPR spectrometer
    News
    04.06.2019
    Development of a miniaturised EPR spectrometer
    Several research institutions are developing a miniaturized electron paramagnetic resonance (EPR) device with industrial partner Bruker to investigate semiconductor materials, solar cells, catalysts and electrodes for fuel cells and batteries. The Federal Ministry of Education and Research (BMBF) is funding the "EPR-on-a-Chip" or EPRoC project with 6.7 million euros. On June 3, 2019, the kick-off meeting took place at the Helmholtz-Zentrum Berlin.
  • Copper oxide photocathodes: laser experiment reveals location of efficiency loss
    Science Highlight
    09.05.2019
    Copper oxide photocathodes: laser experiment reveals location of efficiency loss
    Solar cells and photocathodes made of copper oxide might in theory attain high efficiencies for solar energy conversion. In practice, however, large losses occur. Now a team at the HZB has been able to use a sophisticated femtosecond laser experiment to determine where these losses take place: not so much at the interfaces, but instead far more in the interior of the crystalline material. These results provide indications on how to improve copper oxide and other metal oxides for applications as energy materials.
  • 3D tomographic imagery reveals how lithium batteries age
    Science Highlight
    06.05.2019
    3D tomographic imagery reveals how lithium batteries age
    Lithium batteries lose amp-hour capacity over time. Microstructures can form on the electrodes with each new charge cycle, which further reduces battery capacity. Now an HZB team together with battery researchers from Forschungszentrum Jülich, the University of Munster, and partners in China have documented the degradation process of lithium electrodes in detail for the first time. They achieved this with the aid of a 3D tomography process using synchrotron radiation at BESSY II (HZB) as well at the Helmholtz-Zentrum Geesthacht (HZG). Their results have been published open access in the scientific journal "Materials Today".
  • Inorganic perovskite absorbers for use in thin-film solar cells
    Science Highlight
    29.04.2019
    Inorganic perovskite absorbers for use in thin-film solar cells
    A team at the Helmholtz-Zentrum Berlin has succeeded in producing inorganic perovskite thin films at moderate temperatures using co-evaporation – making post-tempering at high temperatures unnecessary. The process makes it much easier to produce thin-film solar cells from this material. In comparison to metal-organic hybrid perovskites, inorganic perovskites are more thermally stable. The work has been published in Advanced Energy Materials.
  • High-efficiency thermoelectric materials: new insights into tin selenide
    Science Highlight
    24.04.2019
    High-efficiency thermoelectric materials: new insights into tin selenide
    Tin selenide might considerably exceed the efficiency of current record holding thermoelectric materials made of bismuth telluride. However, it was thought its efficiency became enormous only at temperatures above 500 degrees Celsius. Now measurements at the BESSY II and PETRA III synchrotron sources show that tin selenide can also be utilised as a thermoelectric material at room temperature – so long as high pressure is applied.
  • "Molecular scissors" for plastic waste
    Science Highlight
    12.04.2019
    "Molecular scissors" for plastic waste
    A research team from the University of Greifswald and Helmholtz-Zentrum-Berlin (HZB) has solved the molecular structure of the important enzyme MHETase at BESSY II. MHETase was discovered in bacteria and together with a second enzyme - PETase - is able to break down the widely used plastic PET into its basic building blocks. This 3D structure already allowed the researchers to produce a MHETase variant with optimized activity in order to use it, together with PETase, for a sustainable recycling of PET. The results have been published in the research journal Nature Communications.
  • Catalyst research for solar fuels: Amorphous molybdenum sulphide works best
    Science Highlight
    04.04.2019
    Catalyst research for solar fuels: Amorphous molybdenum sulphide works best
    Efficient and inexpensive catalysts will be required for production of hydrogen from sunlight. Molybdenum sulphides are considered good candidates. A team at HZB has now explained what processes take place in molybdenum sulphides during catalysis and why amorphous molybdenum sulphide works best. The results have been published in the journal ACS Catalysis.
  • HZB contributions to special edition on Ultrafast Dynamics with X-ray Methods
    Science Highlight
    02.04.2019
    HZB contributions to special edition on Ultrafast Dynamics with X-ray Methods
    In the new special issue of the "Philosophical Transactions of the Royal Society of London", internationally renowned experts report on new developments in X-ray sources and ultrafast time-resolved experiments. HZB physicists have also been invited to contribute.
  • X-ray analysis of carbon nanostructures helps material design
    Science Highlight
    13.03.2019
    X-ray analysis of carbon nanostructures helps material design
    Nanostructures made of carbon are extremely versatile: they can absorb ions in batteries and supercapacitors, store gases, and desalinate water. How well they cope with the task at hand depends largely on the structural features of the nanopores. A new study from the HZB has now shown that structural changes that occur due to morphology transition with increasing temperature of the synthesis can also be measured directly – using small-angle X-ray scattering. The results have now been published in the journal Carbon.
  • Water is more homogeneous than expected
    Science Highlight
    20.02.2019
    Water is more homogeneous than expected
    In order to explain the known anomalies in water, some researchers assume that water consists of a mixture of two phases even under ambient conditions. However, new X-ray spectroscopic analyses at BESSY II, ESRF and Swiss Light Source show that this is not the case. At room temperature and normal pressure, the water molecules form a fluctuating network with an average of 1.74 ± 2.1% donor and acceptor hydrogen bridge bonds per molecule each, allowing tetrahedral coordination between close neighbours.
  • Spintronics by “straintronics”: Superferromagnetism with electric-field induced strain
    Science Highlight
    14.02.2019
    Spintronics by “straintronics”: Superferromagnetism with electric-field induced strain
    Data storage in today’s magnetic media is very energy consuming. Combination of novel materials and the coupling between their properties could reduce the energy needed to control magnetic memories thus contributing to a smaller carbon footprint of the IT sector. Now an international team led by HZB has observed at the HZB lightsource BESSY II a new phenomenon in iron nanograins: whereas normally the magnetic moments of the iron grains are disordered with respect each other at room temperature, this can be changed by applying an electric field: This field induces locally a strain on the system leading to the formation of a so-called superferromagnetic ordered state.
  • Ultra-thin and extremely efficient: Thin-film tandem cells made of perovskite and CIGSe semiconductors
    Science Highlight
    31.01.2019
    Ultra-thin and extremely efficient: Thin-film tandem cells made of perovskite and CIGSe semiconductors
    An HZB team has fabricated and characterised a thin-film tandem solar cell made of perovskite and CIGSe. They relied on a simple, robust fabrication process that is also suitable for scaling up to large surface areas. The tandem solar cell is a fully thin film device with an impressive efficiency of 21.6 %. With further improvements it might reach efficiencies above 30 %.
  • Batteries with silicon anodes: Neutron experiments show how formation of surface structures reduces amp-hour capacity
    Science Highlight
    28.01.2019
    Batteries with silicon anodes: Neutron experiments show how formation of surface structures reduces amp-hour capacity
    In theory, silicon anodes could store ten times more lithium ions than graphite anodes, which have been used in commercial lithium batteries for many years. However, the amp-hour capacity of silicon anodes so far has been declining sharply with each additional charge-discharge cycle. Now an HZB team at BER II of the HZB in Berlin and the Institut Laue-Langevin in Grenoble has utilised neutron experiments to establish what happens at the surface of the silicon anode during charging and what processes reduce this capacity.
  • Climate change: How could artificial photosynthesis contribute to limiting global warming?
    Science Highlight
    16.01.2019
    Climate change: How could artificial photosynthesis contribute to limiting global warming?

    If CO2 emissions do not fall fast enough, then CO2 will have to be removed from the atmosphere in the future to limit global warming. Not only could planting new forests and biomass contribute to this, but new technologies for artificial photosynthesis as well. An HZB physicist and a researcher at the University of Heidelberg have estimated how much surface area such solutions would require. Although artificial photosynthesis could bind CO2 more efficiently than the natural model, there are still no large modules that are stable over the long term. The team published their calculations in "Earth System Dynamics".

  • Milestone for bERLinPro: photocathodes with high quantum efficiency
    Science Highlight
    07.12.2018
    Milestone for bERLinPro: photocathodes with high quantum efficiency
    A team at the HZB has improved the manufacturing process of photocathodes and can now provide photocathodes with high quantum efficiency for bERLinPro.
  • Molecules that self-assemble into monolayers for efficient perovskite solar cells
    Science Highlight
    23.11.2018
    Molecules that self-assemble into monolayers for efficient perovskite solar cells
    A team at the HZB has discovered a new method for producing efficient contact layers in perovskite solar cells. It is based on molecules that organise themselves into a monolayer. The study was published in Advanced Energy Materials and appeared on the front cover of the journal.
  • Transition metal complexes: mixed works better
    Science Highlight
    14.11.2018
    Transition metal complexes: mixed works better
    A team at BESSY II has investigated how various iron-complex compounds process energy from incident light. They were able to show why certain compounds have the potential to convert light into electrical energy. The results are important for the development of organic solar cells. The study has now been published in the journal PCCP, and its illustration selected for the cover.
  • New records in perovskite-silicon tandem solar cells through improved light management
    Science Highlight
    12.11.2018
    New records in perovskite-silicon tandem solar cells through improved light management
    Using microstructured layers, an HZB team has been able to increase the efficiency of perovskite-silicon tandem solar cells, achieving 25.5 %, which is the highest published value to date. At the same time, computational simulations were utilized to investigate light conversion in various device designs with different nanostructured surfaces. This enabled optimization of light management and detailed energy yield analyses. The study has now been published in Energy & Environmental Science.
  • Graphene on the way to superconductivity
    Science Highlight
    10.11.2018
    Graphene on the way to superconductivity
    Scientists at HZB have found evidence that double layers of graphene have a property that may let them conduct current completely without resistance. They probed the bandstructure at BESSY II with extremely high resolution ARPES and could identify a flat area at a surprising location.
  • Poster award to HZB doctoral student
    News
    19.10.2018
    Poster award to HZB doctoral student
    Frederike Lehmann from the HZB Department Structure and Dynamics of Energy Materials received a poster award at an international conference, the ICTMC-21 in Boulder, Colorado, USA. She presented her results on the synthesis and characterization of hybrid perovskite materials, which are considered interesting candidates for novel solar cells.
  • Nanodiamonds as photocatalysts
    Science Highlight
    18.10.2018
    Nanodiamonds as photocatalysts
    Diamond nanomaterials are considered hot candidates for low-cost photocatalysts. They can be activated by light and can then accelerate certain reactions between water and CO2 and produce carbon-neutral "solar fuels". The EU project DIACAT has now doped such diamond materials with boron and shown at BESSY II how this could significantly improve the photocatalytic properties.
  • Blue phosphorus - mapped and measured for the first time
    Science Highlight
    15.10.2018
    Blue phosphorus - mapped and measured for the first time
    Until recently, the existence of "blue" phosphorus was pure theory: Now an HZB team was able to examine samples of blue phosphorus at BESSY II for the first time and confirm via mapping of their electronic band structure that this is actually this exotic phosphorus modification. Blue phosphorus is an interesting candidate for new optoelectronic devices. The results have been published in Nano Letters.
  • Neutrons scan magnetic fields inside samples
    Science Highlight
    02.10.2018
    Neutrons scan magnetic fields inside samples
    With a newly developed neutron tomography technique, an HZB team has been able to map for the first time magnetic field lines inside materials at the BER II research reactor. Tensorial neutron tomography promises new insights into superconductors, battery electrodes, and other energy-related materials.
  • HZB researchers boost the efficiency of silicon solar cells
    Science Highlight
    02.10.2018
    HZB researchers boost the efficiency of silicon solar cells
    The efficiency of a solar cell is one of its most important parameters. It indicates what percentage of the solar energy radiated into the cell is converted into electrical energy. The theoretical limit for silicon solar cells is 29.3 percent due to physical material properties. In the journal Materials Horizons, researchers from Helmholtz-Zentrum Berlin (HZB) and international colleagues describe how this limit can be abolished. The trick: they incorporate layers of organic molecules into the solar cell. These layers utilise a quantum mechanical process known as singlet exciton fission to split certain energetic light (green and blue photons) in such a way that the electrical current of the solar cell can double in that energy range.
  • Machine learning helps improving photonic applications
    Science Highlight
    28.09.2018
    Machine learning helps improving photonic applications
    Photonic nanostructures can be used for many applications, not just in solar cells, but also in optical sensors for cancer markers or other biomolecules, for example. A team at HZB using computer simulations and machine learning has now shown how the design of such nanostructures can be selectively optimised. The results are published in Communications Physics.
  • Future information technologies: nanoscale heat transport under the microscope
    Science Highlight
    21.08.2018
    Future information technologies: nanoscale heat transport under the microscope
    A team of researchers from the Helmholtz-Zentrum Berlin (HZB) and the University of Potsdam has investigated heat transport in a model system comprising nanometre-thin metallic and magnetic layers. Similar systems are candidates for future high-efficiency data storage devices that can be locally heated and rewritten by laser pulses (Heat-Assisted Magnetic Recording). Measurements taken with extremely short X-ray pulses have now shown that the heat is distributed a hundred times slower than expected in the model system. The results are published in Nature Communications.
  • World record: Fastest 3D tomographic images at BESSY II
    Science Highlight
    08.08.2018
    World record: Fastest 3D tomographic images at BESSY II
    An HZB team has developed an ingenious precision rotary table at the EDDI beamline at BESSY II and combined it with particularly fast optics. This enabled them to document the formation of pores in grains of metal during foaming processes at 25 tomographic images per second - a world record.
  • Insight into loss processes in perovskite solar cells enables efficiency improvements
    Science Highlight
    01.08.2018
    Insight into loss processes in perovskite solar cells enables efficiency improvements
    In perovskite solar cells, charge carriers are mainly lost through recombination occurring at interface defect sites. In contrast, recombination at defect sites within the perovskite layer does not limit the performance of the solar cells at present. Teams from the University of Potsdam and the Helmholtz-Zentrum Berlin (HZB) were able to reach this interesting conclusion through extremely accurate quantitative measurements on 1 cm2 perovskite cells using photoluminescence. Their results contribute to improving  perovskite solar cells and have now been published in Nature Energy.
  • Insight into catalysis through novel study of X-ray absorption spectroscopy
    Science Highlight
    31.07.2018
    Insight into catalysis through novel study of X-ray absorption spectroscopy
    An international team has made a breakthrough at BESSY II. For the first time, they succeeded in investigating electronic states of a transition metal in detail and drawing reliable conclusions on their catalytic effect from the data. These results are helpful for the development of future applications of catalytic transition-metal systems. The work has now been published in Chemical Science, the Open Access journal of the Royal Society of Chemistry.
  • Neutron tomography: Insights into the interior of teeth, root balls, batteries, and fuel cells
    Science Highlight
    05.06.2018
    Neutron tomography: Insights into the interior of teeth, root balls, batteries, and fuel cells
    A team of researchers at Helmholtz-Zentrum Berlin (HZB) and European Spallation Source (ESS) has now published a comprehensive overview of neutron-based imaging processes in the renowned journal Materials Today (impact factor 21.6). The authors report on the latest developments in neutron tomography, illustrating the possible applications using examples of this non-destructive method. Neutron tomography has facilitated breakthroughs in so diverse areas such as art history, battery research, dentistry, energy materials, industrial research, magnetism, palaeobiology and plant physiology.
  • Kesterite solar cells: germanium promises better opto-electronic properties than tin
    Science Highlight
    29.03.2018
    Kesterite solar cells: germanium promises better opto-electronic properties than tin
    Specific changes in the composition of kesterite-type semiconductors make it possible to improve their suitability as absorber layers in solar cells. As a team at the Helmholtz-Zentrum Berlin showed, this is particularly true for kesterites in which tin was replaced by germanium. The scientists examined the samples using neutron diffraction at BER II and other methods. The work was selected for the cover of the journal CrystEngComm.
  • Solar–to-hydrogen conversion: nanostructuring increases efficiency of metal-free photocatalysts by factor eleven
    Science Highlight
    28.02.2018
    Solar–to-hydrogen conversion: nanostructuring increases efficiency of metal-free photocatalysts by factor eleven
    Polymeric carbon nitrides exhibit a catalytic effect in sunlight that can be used for the production of hydrogen from solar energy. However, the efficiency of these metal-free catalysts is extremely low. A team at the Tianjin University in China, in collaboration with a group at the Helmholtz-Zentrum Berlin, has increased the catalytic efficiency of these polymeric carbon nitrides by a factor eleven through a simple process resulting in a larger surface area. The paper was published in the journal Energy & Environmental Science.
  • Luminescent nano-architectures of gallium arsenide
    Science Highlight
    22.02.2018
    Luminescent nano-architectures of gallium arsenide
    A team at the HZB has succeeded in growing nanocrystals of gallium arsenide on tiny columns of silicon and germanium. This enables extremely efficient optoelectronic components for important frequency ranges to be realised on silicon chips.
  • Hidden talents: Converting heat into electricity with pencil and paper
    Science Highlight
    16.02.2018
    Hidden talents: Converting heat into electricity with pencil and paper
    Thermoelectric materials can use thermal differences to generate electricity. Now there is an inexpensive and environmentally friendly way of producing them with the simplest of components: a normal pencil, photocopy paper, and conductive paint are sufficient to convert a temperature difference into electricity via the thermoelectric effect. This has now been demonstrated by a team at the Helmholtz-Zentrum Berlin.
  • 40-year controversy in solid-state physics resolved
    Science Highlight
    06.02.2018
    40-year controversy in solid-state physics resolved
    An international team at BESSY II headed by Prof. Oliver Rader has shown that the puzzling properties of samarium hexaboride do not stem from the material being a topological insulator, as it had been proposed to be. Theoretical and initial experimental work had previously indicated that this material, which becomes a Kondo insulator at very low temperatures, also possessed the properties of a topological insulator. The team has now published a compelling alternative explanation in Nature Communications, however.
  • Perovskite solar cells: perfection not required!
    Science Highlight
    15.01.2018
    Perovskite solar cells: perfection not required!
    Experiments at BESSY II reveal why even inhomogeneous perovskite films are highly functional 
  • Future IT: Antiferromagnetic dysprosium reveals magnetic switching with less energy
    Science Highlight
    06.11.2017
    Future IT: Antiferromagnetic dysprosium reveals magnetic switching with less energy
    HZB scientists have identified a mechanism with which it may be possible to develop a form of magnetic storage that is faster and more energy-efficient. They compared how different forms of magnetic ordering in the rare-earth metal named dysprosium react to a short laser pulse. They discovered that the magnetic orientation can be altered much faster and with considerably less energy if the magnetic moments of the individual atoms do not all point in the same direction (ferromagnetism), but instead point are rotated against each other (anti-ferromagnetism). The study was published in Physical Review letters on 6. November 2017 and on the cover of the print edition.
  • Missing link between new topological phases of matter discovered
    Science Highlight
    17.10.2017
    Missing link between new topological phases of matter discovered
    HZB-Physicists at BESSY II have investigated a class of materials that exhibit characteristics of topological insulators. During these studies they discovered a transition between two different topological phases, one of which is ferroelectric, meaning a phase in the material that exhibits spontaneous electric polarisation and can be reversed by an external electric field. This could also lead to new applications such as switching between differing conductivities.
  • The miracle material graphene: convex as a chesterfield
    Science Highlight
    18.09.2017
    The miracle material graphene: convex as a chesterfield
    Graphene possesses extreme properties and can be utilised in many ways. Even the spins of graphene can be controlled through use of a trick. This had already been demonstrated by a HZB team some time ago: the physicists applied a layer of graphene onto a nickel substrate and introduced atoms of gold in between (intercalation). The scientists now show why this has such a dramatic influence on the spins in a paper published in 2D Materials. As a result, graphene can also be considered as a material for future information technologies that are based on processing spins as units of information.
  • Writing with the electron beam: now in silver
    Science Highlight
    24.07.2017
    Writing with the electron beam: now in silver
    For the first time an international team realized direct writing of silver nanostructures using an electron beam applied to a substrate. Silver nanostructures have the potential to concentrate visible light at the nanoscale. Potential applications include sensor design to detect extremely small traces of specific molecules, as well as devices for optical information processing.
  • New at Campus Wannsee: CoreLab Quantum Materials
    News
    19.06.2017
    New at Campus Wannsee: CoreLab Quantum Materials
    Helmholtz-Zentrum Berlin has expanded its series of CoreLabs for energy materials research. In addition to the five established CoreLabs, it has now set up a CoreLab for Quantum Materials. A research team from the HZB Institute for Quantum Phenomena in New Materials is responsible for the CoreLab and its modern equipment. The CoreLab is also open to experimenters from other research institutes. 
  • New lab for electrochemical interfaces at BESSY II
    News
    14.06.2017
    New lab for electrochemical interfaces at BESSY II
    The Helmholtz-Zentrum Berlin (HZB) is establishing a joint lab together with the Max Planck Society (MPS) to study electrochemical phenomenon at solid/liquid interfaces. The Berlin Joint Lab for Electrochemical Interfaces, or BElChem for short, will employ X-rays from BESSY II to analyse materials for renewable energy production.
  • Better cathode materials for Lithium-Sulphur-Batteries
    Science Highlight
    17.05.2017
    Better cathode materials for Lithium-Sulphur-Batteries
    A team at the Helmholtz-Zentrum Berlin (HZB) has for the first time fabricated a nanomaterial made from nanoparticles of a titanium oxide compound (Ti4O7) that is characterised by an extremely large surface area, and tested it as a cathode material in lithium-sulphur batteries. The highly porous nanomaterial possesses high storage capacity that remains nearly constant over many charging cycles.
  • Proton transfer: Researcher find mecanism to protect biomolecules against light induced damage
    Science Highlight
    07.04.2017
    Proton transfer: Researcher find mecanism to protect biomolecules against light induced damage
    A team at the Helmholtz-Zentrum Berlin (HZB) together with researchers in Sweden and the USA has analysed a mecanism which protects biomolecules such as the DNA against damage by light. They observed how the energy of incoming photons can be absorbed by the molecule without destroying important bonds. The experiments took place at the Linac Coherent Light Source (LCLS) free-electron laser in California as well as the BESSY II synchrotron source at the HZB in Berlin, where with resonant inelastic X-ray-diffraction a very sensitive method is available.
  • How to increase efficiencies of ultrathin CIGSe solar cells
    Science Highlight
    14.03.2017
    How to increase efficiencies of ultrathin CIGSe solar cells
    Nanoparticles at the back help harvesting the light.
  • Fuel cells with PFIA-membranes:
    Science Highlight
    19.12.2016
    Fuel cells with PFIA-membranes:
  • Research for Germany’s energy transition: EMIL@BESSY II approved for the Kopernikus “Power-to-X” project
    News
    21.11.2016
    Research for Germany’s energy transition: EMIL@BESSY II approved for the Kopernikus “Power-to-X” project
    The storage of excess solar and wind power is one of the greatest challenges in Germany’s energy transition. To address this, the German Federal Ministry for Education and Research (BMBF) has created the “Power-to-X” (P2X) project under its Kopernikus programme. P2X will advance research into converting electrical energy from the sun and wind into basic chemical compounds, gaseous energy media, and fuels. A total of 17 research institutions, 26 industrial enterprises, as well as three non-governmental organisations are involved, and the BMBF is funding the first development phase of the project at a level of 30 million Euros. The Helmholtz-Zentrum Berlin will participate in the planned research, using the advanced synthesis capabilities and the BESSY II synchrotron-based X-ray characterization tools at the recently inaugurated EMIL@BESSY II laboratory complex.
  • Methods at BESSY II: Versatile cross-correlator for ultrafast X-ray experiments
    Science Highlight
    14.11.2016
    Methods at BESSY II: Versatile cross-correlator for ultrafast X-ray experiments
    Particularly in the soft X-ray range experimentalists are lacking a broadband method to correlate ultrashort X-ray and laser pulses in space and time. Only recently, a team from Helmholtz-Zentrum Berlin and the University of Potsdam was able to achieve this by utilizing a standard molybdenum-silicon (Mo/Si) multilayer mirror at the FemtoSpeX facility at BESSY II. They use femtosecond laser pulses to modulate the multilayer period under the Bragg condition on a sub-picosecond up to nanosecond timescale which in turn strongly affects the mirror’s X-ray reflectivity. The presented Mo/Si cross-correlator works for the soft up to the hard X-ray regime as well as for a broad range of laser pump wavelengths (mid-IR to UV) and renders this technique as an easy to implement and versatile timing tool for various synchrotron- and lab-based pump-probe experiments. The results are published in the journal of "Structural Dynamics".
  • Methodology advance at HZB: ionic liquids simplify laser experiments on liquid samples
    Science Highlight
    19.10.2016
    Methodology advance at HZB: ionic liquids simplify laser experiments on liquid samples
    An HZB team has developed a new approach to conduct photoemission spectroscopy of molecules in solution. This has been difficult up to now because the sample needed to be situated in vacuum – but liquids evaporate. The work has now demonstrated it is feasible to replace the solvent with an ionic liquid of low vapor pressure, which does not perturb the sample characteristics.  This allows the molecules to be excited with a laser pulse and to record the behaviour of the excited energy states. It provides insight into the physical and chemical processes of novel liquid energy materials that might be employed in organic solar cells or catalysts, for instance.
  • Future Information Technologies: New combinations of materials for producing magnetic monopoles
    Science Highlight
    10.10.2016
    Future Information Technologies: New combinations of materials for producing magnetic monopoles
    An international collaboration at BESSY II has discovered a new method to inscribe exotic magnetic patterns such as magnetic monopoles into thin ferromagnetic films. Such unconventional orientation of magnetic domains might open a new path for the design of energy efficient data storage. The new materials system consists of regular arrays of superconducting YBaCuO-dots covered with an extremely thin permalloy film. A shortly applied external magnetic field leads to the creation of supercurrents within the superconducting dots. These currents produce a complex magnetic field pattern, which is inscribed into the permalloy film above. The results are published in Advanced Science.
  • Nanotechnology for energy materials: Electrodes like leaf veins
    Science Highlight
    27.09.2016
    Nanotechnology for energy materials: Electrodes like leaf veins
    Nano-sized metallic wires are attracting increasing attention as conductive elements for manufacturing transparent electrodes, which are employed in solar cells and touch screen panels. In addition to high electric conductivity, excellent optical transmittance is one of the important parameters for an electrode in photovoltaic applications. An international team headed by HZB scientist Prof. Michael Giersig has recently demonstrated for these applications that networks of metallic mesh possessing fractal-like nano-features surpass other metallic networks in utility. These findings have now been published in the most recent edition of the renowned journal Nature Communications.
  • VI-Conference "Dynamic Pathways in Multidimensional Landscapes 2016"
    News
    19.09.2016
    VI-Conference "Dynamic Pathways in Multidimensional Landscapes 2016"
    Near the museum island, in the heart of Berlin, the International Conference "Dynamic Pathways in Multidimensional Landscapes 2016" has taken place last week. More than 100 international experts met at the Magnus-Haus of the German Physical Society from 12 -16 September 2016.
  • Silicon thin fims in Lithium-Ion-Batteries: Charging observed with neutron measurements
    News
    08.08.2016
    Silicon thin fims in Lithium-Ion-Batteries: Charging observed with neutron measurements
    The capacity of lithium-ion batteries might be increased theoretically by six times by using anodes made of silicon instead of graphite. A team from the Helmholtz-Zentrum Berlin (HZB) Institute of Soft Matter and Functional Materials has observed for the first time in detail how lithium ions migrate into thin films of silicon. It was shown that extremely thin layers of silicon would be sufficient to maximise the load of lithium. The results are published in the journal ACSnano.
  • Two Freigeist Fellows interweave their research at HZB
    News
    01.08.2016
    Two Freigeist Fellows interweave their research at HZB
    Two Freigeist Fellows are conducting research at the HZB Institute for Methods of Material Development through support received from the Volkswagen Foundation. Theoretical chemist Dr. Annika Bande is modelling fast electron processes, while Dr. Tristan Petit is investigating carbon nanoparticles. Annika Bande has now been awarded an ancillary grant of an additional 150,000 Euros from the Volkswagen Foundation to fund another doctoral student position for three years. The doctoral research will connect the two Freigeist research projects with one another.
  • Novel state of matter: Observation of a quantum spin liquid
    Science Highlight
    25.07.2016
    Novel state of matter: Observation of a quantum spin liquid
    A novel and rare state of matter known as a quantum spin liquid has been empirically demonstrated in a monocrystal of the compound calcium-chromium oxide by team at HZB. What is remarkable about this discovery is that according to conventional understanding, a quantum spin liquid should not be possible in this material. A theoretical explanation for these observations has now also been developed. This work deepens our knowledge of condensed matter and might also be important for future developments in quantum information. The results have just been published in Nature Physics.
  • Progress in the application of spin effects in graphene: from the metal to the semiconductor world
    Science Highlight
    16.06.2016
    Progress in the application of spin effects in graphene: from the metal to the semiconductor world
    Graphene on silicon carbide could be an interesting candidate for future spintronik components. Squeezing gold atoms between the semiconducting substrate and graphene does enhance spin-orbit interaction at hot spots and shows ways to controll the spins. First results at BESSY II are now published in Applied Physics Letters.
  • Spintronics: Resetting the future of Heat Assisted Magnetic Recording
    Science Highlight
    14.06.2016
    Spintronics: Resetting the future of Heat Assisted Magnetic Recording
    A HZB team has examined thin films of Dysprosium-Cobalt sputtered onto a nanostructured membrane at BESSY II. They showed that new patterns of magnetization could be written in a quick and easy manner after warming the sample to only 80 °Celsius, which is a much lower temperature as compared to conventional Heat Assisted Magnetic Recording systems. This paves the way to fast and energy efficient ultrahigh density data storage. The results are published now in the new journal Physical Review Applied.
  • Ferrous chemistry in aqueous solution unravelled
    Science Highlight
    11.05.2016
    Ferrous chemistry in aqueous solution unravelled
    An HZB team has combined two different analytical methods at the BESSY II synchrotron source in order to extract more information about the chemistry of transition-metal compounds in solution. These kinds of compounds can act as catalysts to promote desirable reactions in energy materials, but their behaviour has not been completely understood thus far.  The team demonstrated how a detailed picture of the electronic states can be ascertained by systematically comparing all of the interactive electronic processes in a simple system of aqueous iron(II).  The results have now been published in Scientific Reports, the open access journal from Nature Group publishing.
  • Helmholtz Innovation Labs: HySPRINT at HZB
    News
    10.05.2016
    Helmholtz Innovation Labs: HySPRINT at HZB
    HZB will be setting up the new Helmholtz HySPRINT Innovation Lab for jointly developing new combinations of materials and processes in energy applications with commercial partners. Silicon and metal-organic perovskite crystals will be the centre point of the Lab’s work. The Helmholtz Association is supporting the project for the next five years with 1.9 million Euros from its Initiative and Networking Fund, with additional contributions from HZB itself as well as from industry.
  • Spintronics for future information technologies: spin currents in topological insulators controlled
    Science Highlight
    29.04.2016
    Spintronics for future information technologies: spin currents in topological insulators controlled
    An international team headed by HZB researcher Jaime Sánchez-Barriga has shown how spin-polarised currents can be initiated in a controlled manner within samples of topological insulator material. In addition, they were able to manipulate the orientation of the spins of these currents. They thereby demonstrated that this class of materials is suitable for data processing based on spin. The work has been published in the renowned periodical Physical Review B and was selected as “Editor’s Suggestion” article.
  • Priority programme for topological insulators begins second funding period
    News
    04.04.2016
    Priority programme for topological insulators begins second funding period
    Applicants for support funds to conduct research on topological insulators met at HZB Adlershof on February 15th and 16th. This meeting dealt with the second period of funding for the SPP 1666 Priority programme of the German Research Foundation (DFG) that runs from mid-2016 to 2019. Researchers from across Germany contribute their specific expertise and work together in these Priority programmes (SPPs).
  • Solar fuels:a refined protective layer for the “artificial leaf”
    Science Highlight
    21.03.2016
    Solar fuels:a refined protective layer for the “artificial leaf”
    A team at the HZB Institute for Solar Fuels has developed a process for providing sensitive semiconductors for solar water splitting (“artificial leaves”) with an organic, transparent protective layer. The extremely thin protective layer made of carbon chains is stable, conductive, and covered with catalysing nanoparticles of metal oxides. These accelerate the splitting of water when irradiated by light. The team was able to produce a hybrid silicon-based photoanode structure that evolves oxygen at current densities above 15 mA/cm2. The results have now been published in Advanced Energy Materials.

  • Measuring chemistry: local fingerprint of hydrogen bonding captured in experiments
    Science Highlight
    16.03.2016
    Measuring chemistry: local fingerprint of hydrogen bonding captured in experiments
    A team from Helmholtz-Zentrum Berlin has been able for the first time to measure how new bonds influence molecules: they have reconstructed the “energy landscape” of acetone molecules using measurement data from the Swiss Light Source (SLS) of the Paul Scherrer Institut, and thereby empirically established the formation of hydrogen bonds between acetone and chloroform molecules. The results have been published in Nature Scientific Reports and assist in understanding fundamental phenomena of chemistry.
  • Metal Oxide Sandwiches:  New option to manipulate  properties of interfaces
    Science Highlight
    04.02.2016
    Metal Oxide Sandwiches: New option to manipulate properties of interfaces
    A Franco-German cooperation has investigated a sandwich system of transition metal oxides at BESSY II. The scientists discovered a new option to control properties of the interface between the two layers, for instance the amount of charge transferred from one layer to the other or the emergence of ferromagnetism.  Their insights might help to create new properties at the interface, not present in the primary materials, maybe even novel forms of High Tc superconductivity.
  • Alternative method for the representation of microstructures in polycrystalline materials
    Science Highlight
    18.12.2015
    Alternative method for the representation of microstructures in polycrystalline materials
    Also Raman microspectroscopy in an optical microscope provides the means to determine local crystal orientations of polycrystalline materials over large sample areas. This method can be used alternatively to electron backscatter diffraction in a scanning electron microscope. It was shown by a team from Helmholtz-Zentrum Berlin and the Federal Institute for Materials Research and Testing (BAM) that both characterization techniques result in similar orientation distribution maps on areas of several hundreds of square micrometers.
  • Whispering gallery modes in Silicon nanocones intensify luminescence
    Science Highlight
    26.11.2015
    Whispering gallery modes in Silicon nanocones intensify luminescence
    Silicon, a semiconducting material, reveals new talents when reduced to nanoscopic dimensions. A joint team at the HZB Institute of Nanoarchitectures for Energy Conversion and the Max Planck Institute for the Science of Light (MPL) has demonstrated this. Silicon nanocones generate 200 times as much infrared luminescence as comparably sized nanocolumns when excited by visible light. Modelling and experimental results show that due to their geometry, cones are able to sustain what is referred to as whispering gallery modes at infrared wavelengths which can intensify the silicon luminescence. New applications are conceivable, including silicon-based nanolasers.
  • Filming microscopic and macroscopic changes within materials
    News
    19.11.2015
    Filming microscopic and macroscopic changes within materials
    The EDDI beamline at BESSY II is now offering even more options. It has recently become possible to also obtain high-resolution three-dimensional images of microscopic structure with it, up to four such tomographies per second are possible. X-ray diffraction (energy-dispersive diffraction) can simultaneously be carried out to draw conclusions about the crystal structure of the material just as before.
  • BESSY II electron highway gets second lane
    News
    11.11.2015
    BESSY II electron highway gets second lane
    The particle accelerator team at Helmholtz-Zentrum Berlin (HZB) has demonstrated that BESSY II, the 3rd generation synchrotron radiation source in Berlin, can be operated with not just one, but two simultaneous electron paths. By precisely tuning the magnetic components, physicists can create an additional orbital path. Packets of electrons can travel along it and emit intense light pulses at the experiment stations. This could provide the user community with the option to select light pulses from either path as needed in their experiments. The newly developed orbital mode has already been stably implemented and initial tests at the experiment stations (beamlines) show promising results. HZB is the first to enter this new territory and at the same time has reached another milestone in its pioneering BESSY-VSR project.
  • Poster award to Markus Kubin
    News
    20.10.2015
    Poster award to Markus Kubin
    At the International Conference on X-Ray Absorption Fine Structure Markus Kubin has been selected to receive one out of five poster awards. More than 300 posters have been presented at the poster session.
  • Scientists demonstrate how to improve ultrathin CIGSe solar cells by nanoparticles
    Science Highlight
    15.10.2015
    Scientists demonstrate how to improve ultrathin CIGSe solar cells by nanoparticles
    CIGSe solar cells  are made of a thin chalcopyrite layer consisting of Copper, Indium, Gallium and Selenium and can reach high efficiencies. Since Indium is becoming scarce and expensive, it is interesting to reduce the active CIGSe layer, which however decreases the efficiency quite strongly.  Now, scientists at Helmholtz-Zentrum Berlin have produced high quality ultrathin CIGSe layers and increased their efficiency by an array of tiny nanoparticles between the back contact and the active layer.
  • Graphene as a front contact for silicon-perovskite tandem solar cells
    Science Highlight
    02.10.2015
    Graphene as a front contact for silicon-perovskite tandem solar cells
    HZB team develops elegant process for coating fragile perovskite layers with graphene for the first time. Subsequent measurements show that the graphene layer is an ideal front contact in several respects.
  • Catalysis research strengthened: Helmholtz-Zentrum Berlin participates in newly approved Einstein Center for Catalysis
    News
    28.09.2015
    Catalysis research strengthened: Helmholtz-Zentrum Berlin participates in newly approved Einstein Center for Catalysis
    The Einstein Foundation will fund the new Einstein Center for Catalysis (EC2) beginning in 2016 in which Technical University Berlin (TU Berlin) and selected non-university institutions in Berlin will be participating. Prof. Emad Aziz, head of the HZB Institute for Methods of Materials Research at Helmholtz-Zentrum Berlin will be taking part in setting up the institution. His team will be contributing particular expertise in analytics of ultrafast processes in catalytic reactions.
  • Charge transport in hybrid silicon solar cells
    Science Highlight
    17.08.2015
    Charge transport in hybrid silicon solar cells
    An HZB team headed by Prof. Silke Christiansen has made a surprising discovery about hybrid organic/inorganic solar cells. Contrary to expectations, a diode composed of the conductive organic PEDOT:PSS and an n-type silicon absorber material behaves more like a pn junction between two semiconductors than like a metal-semiconductor contact (Schottky diode). Their results have now been published in the Nature journal Scientific Reports and could point the way toward improvements in hybrid solar cells.
  • Transparent, electrically conductive network of encapsulated silver nanowires – a novel electrode for optoelectronics
    Science Highlight
    31.07.2015
    Transparent, electrically conductive network of encapsulated silver nanowires – a novel electrode for optoelectronics
    A team headed by Prof. Silke Christiansen has developed a transparent electrode with high electrical conductivity for solar cells and other optoelectronic components – that uses minimal amounts of material. It consists of a random network of silver nanowires that is coated with aluminium-doped zinc oxide. The novel electrode requires about 70 times less silver than conventional silver grid electrodes, but possesses comparable electrical conductivity.
  • Spins in Graphene with a Hedgehog Texture
    Science Highlight
    27.07.2015
    Spins in Graphene with a Hedgehog Texture
    HZB researchers demonstrate a fundamental property of the electron spin in graphene
  •  Depletion and enrichment of chlorine in perovskites observed
    Science Highlight
    10.07.2015
    Depletion and enrichment of chlorine in perovskites observed
    X-ray spectroscopy at BESSY II reveals inhomogenous distribution of chlorine in a special class of perovskite materials. The discovery could help to enhance efficiencies of perovskite thin film solar cells by controlled processing to optimize the chlorine distribution.
  •  HZB presents research on thermoelectrics
    News
    07.07.2015
    HZB presents research on thermoelectrics
    The annual "International Conference on Thermoelectrics (ICT)” and the "European Conference on Thermoelectrics (ECT)” took place together from 29 June to 02 July 2015 in Dresden, Germany. For the first time, HZB participated in this international multidisciplinary meeting. The HZB Department "Methods for Characterization of Transport Phenomena in Energy Materials" headed by Dr. Klaus Habicht presented their research in two talks and one poster.
  • New technique enables magnetic patterns to be mapped in 3D
    News
    07.07.2015
    New technique enables magnetic patterns to be mapped in 3D
    An international collaboration has succeeded in using synchrotron light to detect and record the complex 3D magnetisation in wound magnetic layers. This technique could be important in the development of devices that are highly sensitive to magnetic fields, such as in medical diagnostics for example. Their results are published now in Nature Communications.
  • Crystal structure and magnetism – new insight into the fundamentals of solid state physics
    News
    06.07.2015
    Crystal structure and magnetism – new insight into the fundamentals of solid state physics
    HZB team decodes relationship between magnetic interactions and the distortions in crystal structure within a geometrically “frustrated” spinel system
  • Green solutions with diamond materials:
    News
    02.07.2015
    Green solutions with diamond materials:
    Horizon 2020 invests 3.9 million Euro in research project to convert CO2 into fuels using sunlight and diamond materials
  • Towards graphene biosensors
    Science Highlight
    24.06.2015
    Towards graphene biosensors
    For the first time, a team of scientists has succeeded in precisely measuring and controlling the thickness of an organic compound that has been bound to a graphene layer. This might enable graphene to be used as a sensitive detector for biological molecules in the future.
  • Realistic computer model of battery electrodes
    Science Highlight
    02.06.2015
    Realistic computer model of battery electrodes
    A research team has developed a new approach for more realistic computer models of battery electrodes. They combined images from synchrotron tomography that capture three-dimensional structure at micron resolution with those from an electron microscope that can even resolve nanometre-scale features over a small section. They were able to transfer these nano-features to areas beyond the section using a mathematical model. Properties and processes within battery electrodes can now be simulated highly realistically using this method.
  • Poster award for MatSEC PhD student at the MRS Spring Meeting
    News
    29.05.2015
    Poster award for MatSEC PhD student at the MRS Spring Meeting
    The poster contribution of Kai Neldner (HZB-Department Crystallography) was awarded a poster price of the Symposium "Thin-Film Compound Semiconductors" at the MRS Spring Meeting in San Francisco. Kai Neldner, a PhD student in the HZB Graduate School "Materials for Solar Energy Conversion" (MatSEC) has presented results on structural properties of Kesterites (Cu2ZnSnS4 - CZTS) in relation to its stoichiometry deviations.
  • Joint  Lab BeJEL receives 1.4 million EUR grant
    News
    27.05.2015
    Joint Lab BeJEL receives 1.4 million EUR grant
    The Berlin Joint EPR Laboratory (BeJEL) operated by HZB and Freie Universität Berlin has pulled in six of 27 subprojects within a DFG priority program to address“New Frontiers in Sensitivity for EPR Spectroscopy – from Biological Cells to Nano Materials”.
  •  Poster Award for HZB-Postdoc at EMRS Spring Meeting
    News
    27.05.2015
    Poster Award for HZB-Postdoc at EMRS Spring Meeting
    During the spring meeting 2015 of the European Materials Research Society the Poster contribution of  Dr. Ah Reum Jeong (HZB-Institute for Heterogeneous Material Systems) was selected for an award.  The young scientist has presented results on electronic and structural properties in relation to chemical composition of molybdenum oxide layers, which are widely applied in photovoltaic as well as optoelectronic devices.
  • New options for spintronic devices: Switching between 1 and 0 with low voltage
    Science Highlight
    18.05.2015
    New options for spintronic devices: Switching between 1 and 0 with low voltage
    Scientists from Paris and Helmholtz-Zentrum Berlin have been able to switch ferromagnetic domains on and off with low voltage in a structure made of two different ferroic materials. The switching works slightly above room temperature. Their results, which are published online in  Scientific Reports, might inspire future applications in low-power spintronics, for instance for fast and efficient data storage.
  • Artificial photosynthesis: New, stable photocathode with great potential
    Science Highlight
    13.05.2015
    Artificial photosynthesis: New, stable photocathode with great potential
    A team at the HZB Institute for Solar Fuels has developed a new composite photocathode for generating hydrogen with high quantum efficiency using sunlight. This enables solar energy to be stored chemically.The photocathode consists of a thin film of chalcopyrite produced by HZB/PVcomB coated with a newly developed thin film of photoresistant titanium dioxide containing platinum nanoparticles. This layer does not only protect the chalcopyrite thin film from corrosion, it additionally acts as a catalyst to speed-up the formation of hydrogen as well as being a novel photodiode itself that even shows photoelectric current density and voltage comparable to those of a chalcopyrite-based thin film solar cell.
  • Inkjet printing process for Kesterite solar cells
    Science Highlight
    06.05.2015
    Inkjet printing process for Kesterite solar cells
    A research team at HZB has developed an inkjet printing technology to produce kesterite thin film absorbers (CZTSSe). Based on the inkjet-printed absorbers, solar cells with total area conversion efficiency of up to 6.4 % have been achieved. Although this is lower than the efficiency records for this material class, the inkjet printing minimizes waste and has huge advantages for industrial production.
  • EU funding strengthens solar cell research at HZB
    News
    29.04.2015
    EU funding strengthens solar cell research at HZB
    Marcus Bär and his team are participating in two international projects being funded under the EU Horizon 2020 research programme. Both research projects are concerned with development and optimisation of high-efficiency thin-film solar cells based on chalcopyrites (“Sharc 25") and kesterites (“SWInG”). These two projects will together bring in about 900,000 EUR of additional research funding for solar cell research.
  • Learning by eye: silicon micro-funnels increase the efficiency of solar cells
    Science Highlight
    24.02.2015
    Learning by eye: silicon micro-funnels increase the efficiency of solar cells
    A biological structure in mammalian eyes has inspired a team headed by Silke Christiansen to design an inorganic counterpart for use in solar cells. With the help of conventional semiconductor processes, they etched micron-sized vertical funnels shoulder-to-shoulder in a silicon substrate. Using mathematical models and experiments, they tested how these kind of funnel arrays collect incident light and conduct it to the active layer of a silicon solar cell. Their result: this arrangement of funnels increases photo absorption by about 65% in a thin-film solar cell fitted with such an array and is reflected in considerably increased solar cell efficiency, among other improved parameters.
  • Stretch and relax! – Losing one electron switches magnetism on in dichromium
    Science Highlight
    23.02.2015
    Stretch and relax! – Losing one electron switches magnetism on in dichromium
    An international team of scientists from Berlin, Freiburg and Fukuoka has provided the first direct experimental insight into the secret quantum life of dichromium. Whereas in its normal state the 12 valence electrons form a strong multiple bond between the two chromium atoms, removing only one electron changes the situation dramatically: 10 electrons localize and align their spins, thus resulting in ferromagnetic behavior of the dichromium-kation. The bonding is done by one electron only, resulting in a much weaker bond. The scientists used the unique Nanocluster Trap experimental station at the BESSY II synchrotron radiation source at Helmholtz-Zentrum Berlin and published their results in the Journal Angewandte Chemie.
  • Details of a crucial reaction: Physicists uncover oxidation process of carbon monoxide on a ruthenium surface
    Science Highlight
    12.02.2015
    Details of a crucial reaction: Physicists uncover oxidation process of carbon monoxide on a ruthenium surface
    An international team has observed the elusive intermediates that form when carbon monoxide is oxidized on a hot ruthenium metal surface. They used ultrafast X-ray and optical laser pulses at the SLAC National Accelerator Laboratory, Menlo Park, California. The reaction between carbon monoxide and adsorbed oxygen atoms was initiated by heating the ruthenium surface with optical laser pulses. Directly afterwards, changes in the electronic structure of oxygen atoms were probed via X-ray absorption spectroscopy as they formed bonds with the carbon atoms.The observed transition states are consistent with density functional theory and quantum oscillator models.
  • “VEKMAG” at BESSY II creates 3D magnetic fields in samples
    News
    15.01.2015
    “VEKMAG” at BESSY II creates 3D magnetic fields in samples
    Together with HZB, teams from the Universität Regensburg, from the Freie Universität Berlin and from  the  Ruhr Universität Bochum have jointly set up a unique measurement station at BESSY II: a vector electromagnet consisting of three mutually perpendicular Helmholtz coils which enables  setting the local magnetic field at the sample position  to any orientation desired. The first measurements of magnetic materials, spin systems, and nanostructured magnetic samples are scheduled for early 2015.