HZB Newsroom

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.

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. 

An art installation will be erected in front of the entrance to the BESSY building. The sculpture was chosen in a competion. It invites people to sit down and exchange ideas.

On Friday, 19 April 2024, the Scientific Director of Helmholtz-Zentrum Berlin, Bernd Rech, and the President of the Korea Institute of Energy Research (KIER), Yi Chang-Keun, signed a Memorandum of Understanding (MOU) in Daejeon (South Korea).

Burning biomass for cooking causes harmful environmental and health issues. The German-South African GreenQUEST initiative is developing a clean household fuel. It aims to reduce climate-damaging CO₂ emissions and to improve access to energy for households in sub-Saharan Africa.

Registration for Quantsol is now open!

The International Summer School on Photovoltaics and New Concepts of Quantum Solar Energy Conversion (Quantsol) will be held in September 1-8, 2024 in Hirschegg, Kleinwalsertal, Austria. The school is organised by the Helmholtz-Zentrum Berlin and the Technical University of Ilmenau. Applications can be submitted through the school’s homepage until Friday 31^st of May 2024, 23.59h CET.

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.

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.

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.

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. 

Dr. Artem Musiienko has been awarded a special prize for his groundbreaking new method for characterising semiconductors. At the recent annual conference of the Marie Curie Alumni Association (MCAA) in Milan, Italy, he received the MCAA Award for the best innovation. Since 2023, Musiienko has been carrying out his research project with a postdoctoral fellowship from the Marie Sklodowska Curie Actions in Antonio Abate's department, Novel Materials and Interfaces for Photovoltaic Solar Cells (SE-AMIP).

Dr Sebastian Keckert has been awarded the Young Scientist Award for Accelerator Physics of the German Physical Society (DPG). The prize is endowed with 5000 euros and was presented to him on 21.03. during the spring conference in Berlin. It honours the physicist's outstanding achievements in the development of new superconducting thin-film material systems for cavities.

After the egg has been fertilized by a sperm, the surrounding egg coat tightens, mechanically preventing the entry of additional sperm and the ensuing death of the embryo. A team from the Karolinska Institutet has now gained this new insight through measurements at the X-ray light sources BESSY II, DLS and ESRF. 

New states of order can arise in quantum magnetic materials under magnetic fields. An international team has now gained new insights into these special states of matter through experiments at the Berlin neutron source BER II and its High-Field Magnet. BER II served science until the end of 2019 and has since been shut down. Results from data at BER II are still being published.

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.

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.

Physicist Dr Robert Seidel has been awarded a Consolidator Grant by the European Research Council (ERC). Over the next five years, he will receive a total of two million euros for his research project WATER-X. Seidel will use state-of-the-art X-ray techniques at BESSY II to study nanoparticles in aqueous solution for the photocatalytic production of "green" hydrogen.

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 Hf_0.5Zr_0.5O₂ 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.

Since 2017, the German Cyclists' Federation (ADFC) has been awarding the EU-wide "Bicycle-Friendly Employer" certification. The Helmholtz-Zentrum Berlin has now been awarded the coveted silver seal. With this, the HZB wants to be even more attractive as an employer, especially for international applicants.

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 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.

The new HZB magazine lichtblick is out! Topics are: green hydrogen, construction projects and green construction for Ukraine, ... We invite you to browse through the online edition.

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.

The Alliance of German Science Organisations, to which the Helmholtz Association also belongs, emphatically condemns any kind of anti-democratic and inhuman endeavours.

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.

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).

Wir trauern um unseren ehemaligen Kollegen und Leiter des BENSC-Nutzerbüros am damaligen Hahn-Meitner-Institut (HMI, später HZB Nutzerbüro Neutronen) Dr. Hans-Anton Graf. Er verstarb nach einem ereignisreichen Leben und längerer Krankheit am 30. Dezember 2023 im Alter von 78 Jahren. Hans-Anton Graf war 1977 bis 2010 in der Neutronenforschung am HMI/HZB tätig.

Yan Lu is appointed new Professor of Hybrid Materials for Electrochemical Energy Storage and Conversion at Friedrich Schiller University Jena together with HZB. Congratulations!

Processing materials on the nanoscale, producing prototypes for microelectronics or analysing biological samples: The range of applications for finely focused ion beams is huge. Experts from the EU collaboration FIT4NANO have now reviewed the many options and developed a roadmap for the future. The article, published in “Applied Physics Review”, is aimed at students, users from industry and science as well as research policy makers.

Prof. Jörg Eichler war von 1971 bis 1973 wissenschaftlicher Geschäftsführer des Hahn-Meitner-Instituts (HMI), aus dem später zusammen mit BESSY das HZB entstanden ist.  Am 1. Januar 2024 feierte Prof. Jörg Eichler nun seinen 90sten Geburtstag. Das HZB sendet herzliche Glückwünsche.

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. 

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.

The Highlights 2022 report on a selection of the most important research results and events at HZB.

Several HZB research teams are participating in the new SFB 1636 "Elementary processes of light-driven reactions on nanoscale metals".

Many enzymes promise to break down plastic. But what works well in the lab often fails on a large scale. Now a new study by Gert Weber, HZB, Uwe Bornscheuer, University of Greifswald, and Alain Marty, Chief Scientific Officer of Carbios, shows how raising the bar for laboratory experiments could help identify promising approaches more quickly. The team demonstrated the new standards on four newly discovered enzymes.

It really is a problem: Microplastics are everywhere. Now, an HZB and University Potsdam team developed a method that for the first time enables us to precisely localise microplastics in soil. The combined 3D tomographies by neutrons and X-rays show exactly the location of particles and structural changes that can affect water flows and soil properties.

Every year, countless articles are published in specialist journals. The information service provider Clarivate uses a recognised method to measure the influence of the published articles on the respective subject area. According to this year's evaluation, HZB researcher Steve Albrecht is one of the most "highly cited researchers" having a significant influence on his field. Albrecht and his team have been involved in several world records for tandem solar cells in recent years and have published the results in high-ranking scientific journals. 

HZB is aware of its social responsibility. Now, HZB’s Greenhouse Gas Report is here, after being externally verified, and identifies the main sources of emissions. The report provides the basis for significantly reducing greenhouse gas emissions.

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.

On Thursday, 12 October 2023, Michelle Browne received a prestigious award in Hamburg: The "Curious Mind Award" in the category "Mobility, Energy and Sustainable Business" by manager magazin. 

With a strong commitment to further investment in research and innovation, the special conference of the East German Minister-Presidents came to an end on 19 October 2023. The special conference, chaired by Saxony's Minister-President Michael Kretschmer, was also attended by Federal Research Minister Bettina Stark-Watzinger and the Federal Government Commissioner for Eastern Germany, Carsten Schneider.
The special conference was hosted by the Helmholtz-Zentrum Berlin, based in Berlin-Adlershof with BESSY II light source and its energy research.

With great concern, we are following the news from Israel. We are stunned by the massive terrorist violence causing many victims and unbearable human suffering. We condemn the attacks by Hamas on Israel and its citizen in the strongest possible terms.

The first high-level event of the Green Deal Ukraina (GDU) project took place in October in Kyiv, Ukraine, attended by more than 150 participants. This first gathering and formal launch took place at an important moment: EU will share a new report on the countries progress towards EU and Ukraine will respond by sharing its own analysis, called pre-screening.

It already works: there are several approaches to using solar energy to split water and produce hydrogen. Unfortunately, this green hydrogen has so far been more expensive than grey hydrogen from natural gas. A study by Helmholtz-Zentrum Berlin (HZB) and Technische Universität Berlin now shows how green hydrogen from sunlight can become profitable.

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.

Tandem solar cells achieve high efficiencies: by combining two different types of solar cells, more sunlight is converted into electricity. PV manufacturer Qcells and a HZB team led by Dr. Kári Sveinbjörnsson and Bor Li have developed the technology to an extent, that Qcells invested in setting up a pilot line for the development of tandem cells in Saxony-Anhalt. For this successful transfer into industrial application, both researchers received the Technology Transfer Prize of the Helmholtz-Zentrum Berlin worth 5,000 euros, on 4. October 2023.

A multidisciplinary team from Helmholtz-Zentrum Berlin (HZB) and Forschungszentrum Jülich (FZJ) is researching and improving novel tandem solar cells in order to bring them into application. For their approach and research achievements, Steve Albrecht, Antonio Abate and Eva Unger from HZB and Michael Saliba from FZJ received the High Impact Award on 27 September 2023. With the award, which comes with 50,000 euros in prize money, the Helmholtz Association and the Donors’ Association for the Promotion of Sciences and Humanities in Germany honour innovative approaches that have the potential to act as game-changers.

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.

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.

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.

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.

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.

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.

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. 

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.

Friedrich Schiller University Jena and the Helmholtz-Zentrum Berlin (Helmholtz Centre for Materials and Energy, HZB) will jointly establish the "Helmholtz Institute for Polymers in Energy Applications" (HIPOLE) on 1 July 2023. The aim of HIPOLE is to develop sustainable polymer materials for energy technologies that can be rapidly brought into application, in particular polymer-based batteries and perovskite solar cells with polymer additives. HIPOLE will be funded with up to 5.5 million euros per year by the Federal Ministry of Education and Research (BMBF, 90%) and the Free State of Thuringia (10%). In the start-up phase until 2028, the Free State of Thuringia will additionally fund the new institute with more than ten million euros and take over the financing of the construction costs for the laboratories and offices.

A team of HZB has investigated the electronic structure of  Au₂Pb at BESSY II by angle-resolved photoemission spectroscopy across a wide temperature range: The results are in accordance with the electronic structure of a three-dimensional topological Dirac semimetal, in agreement with theoretical calculations.

e will open our doors for the Long Night of the Sciences. Get exciting insights into our energy research, visit laboratories and ask us your questions about the energy transition. Our school lab invites you to take part in hands-on experiments - and a science show will keep you pumped up and amazed! Please bring your identity card!     

Nach längerer Krankheit starb Prof. Dr. Hans Ackermann am 25. März 2023 im Alter von 87 Jahren. Hans Ackermann war in vielen Funktionen für das Hahn-Meitner-Institut in den 1980er und 1990er Jahren tätig. In dieser Zeit war er einer der führenden Forscher auf dem Gebiet der nuklearen Festkörperphysik, der sich prägend und intensiv für diese Forschungsrichtung und ihre Förderung eingesetzt hat.

On 11 June 2023, Professor Dr Wolfgang Gudat will turn 80. From 1989 to 2000, Wolfgang Gudat was scientific director of BESSY. Under his leadership, the BESSY II project was approved and the storage ring in Adlershof was built and equipped with state-of-the-art instruments. He founded the Friends of HZB and is honorary chairman of the association. On his birthday, his colleagues and the HZB management wish him all the best!

Green Deal Ukraina, funded by the German Federal Ministry of Education and Research, is working with partner institutions in Ukraine and Poland to establish an energy and climate think tank in the capital, Kiev. The aim is to provide independent and evidence-based advice on rebuilding a sustainable energy system in Ukraine. After all, the implementation of energy and climate legislation is a prerequisite for Ukraine's accession to the EU. The project started on 1 June 2023 and will run for four years.

In February 2023, the Scientific Director of Helmholtz-Zentrum Berlin was elected Corresponding Member of the Slovenian Academy of Engineering (IAS).

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 La_2/3Sr_1/3MnO₃ (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.

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.

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.

Charlotte Klar and Katharina Austermann (both 18) have already come a long way: With their experiments on pyrolytic graphite, they are trying to solve a puzzle they found in the technical literature on diamagnetism. With their work, they convinced both the Jugend-forscht-Jury at the Berlin South Regional Competition and the Berlin Competition. Now, they will join the national competition which will take place from 18 to 21 May in Bremen.

Are you a 10th to 13th grade student interested in mathematics and science? Then secure your free VIP ticket for a tour with exciting experiments and insights during the Long Night of Science! Meet female scientists who are passionate about making our world a better place! 17.06. , from 5.30 pm, Adlershof Research Campus.

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.

Prof. Dr. Jens Eisert heads the Quantum Computation and Simulation research group, which is jointly funded by Freie Universität Berlin and HZB. The theoretical physicist recently received an Advanced Grant from the European Research Council ERC for his research project "DebuQC". But Eisert is not only an award-winning scientist, he is also concerned about global warming. Last year, on the initiative of Ryan Sweke, he and his team published a proposal that deserves attention: scientific publications on theoretical physics or chemistry could include a simple table listing the greenhouse gases emitted during the research. This would raise awareness of the fact that research is not climate neutral.

Dr. Wenxi Wang is working in the team of Prof. Yan Lu as Humboldt Foundation postdoctoral fellow. He studied at the Southern University of Science and Technology in Shenzhen, China, and completed his doctorate at the King Abdullah University of Science and Technology in Saudi Arabia. He specialises in the precise design of organic electrodes for lithium-sulfur and zinc-ion batteries and the investigation of the interactions between ions and active materials.

In diesem Jahr fokussiert die Veranstaltung des Helmholtz-Zentrum Berlin für Materialien und Energie die Bauwerkintegrierte Photovoltaik (BIPV). Dabei betrachten wir das Material, die Technologie, den Baustoff sowie Entwurfsparameter und den Bauablauf. Begleitet wird die Veranstaltung von Materialproben und Vorträgen.

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.

End of March, a delegation from the Czech Republic visited HZB at the Wannsee campus. The programme included a visit to the apprentices’ workshop and exchanges regarding opportunities for apprenticeships and upskilling at HZB.

The HZB researcher Rutger Schlatmann has been elected as the new Chair of the platform ETIP-PV, which brings together representatives of science, industry and politics from all over Europe. We interviewed him about the current boom – and about why the photovoltaics ship has not yet sailed for the EU.

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.

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 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.

The SXR2023 (Principles of Functionality from Soft-X-Ray Spectroscopy) brings together young and experienced scientists to discuss recent scientific highlights, trends, and current advances with soft X-ray spectroscopy. Our goal is to further understanding on the atomic level. The impetus is to influence and ideally shape functionality in materials and molecular systems. In this effort, scientists cross intentionally the boundaries between physics, chemistry and materials and focus on the unifying aspects of functionality. Insights to the governing principles are often based on the combination of experiment with first principles theory and models. Thus a profound description of X-ray matter interaction — creating the spectroscopic observables — is always underlying.

Prof. Dr. Catherine Dubourdieu heads the Institute “Functional Oxides for Energy-Efficient Information Technology” at HZB and is Professor at the Physical and Theoretical Chemistry division at Freie Universität Berlin. The physicist and materials scientist specialises in nanometre-sized functional oxides and their applications in information technologies. She has now been awarded a prestigious ERC Advanced Grant for her research project “LUCIOLE”, which aims at combining ferroelectric polar textures with conventional silicon technologies.

Prof. Dr. Jens Eisert conducts research at the Dahlem Center for Complex Quantum Systems at Freie Universität Berlin and heads the joint research group with HZB for quantum computing and simulation. With his award-winning research project "DebuQC", he wants to explore the metaphorical boundary of the classical and quantum worlds. It is already his third ERC grant that Jens Eisert has received. The professor of theoretical quantum physics and his team want to clarify essential research questions about quantum technology and also explore the limits of this promising technology.

The energy transition presents us all with major challenges. We need not only electricity from renewable sources, but also storage solutions. At the Wannsee site, Yan Lu's team is researching novel lithium-sulphur batteries that can store much more energy than conventional batteries. The laboratory is unique in the Berlin-Brandenburg research landscape. In the cover story, the head of department tells us what motivates her about her work.

The Helmholtz Association has selected three new innovation platforms that will now be funded. HZB is involved in two of them: The Innovation Platform on Accelerator Technologies HI-ACTS is intended to open up modern accelerators for a wide range of applications, while the Innovation Platform Solar TAP is intended to bring new ideas from the laboratories of photovoltaics research more quickly into an application. In total, HZB will receive 4.2 million euros in grants from the Pact for Research and Innovation over the next three years.

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.

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.

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.

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.

For the past two years, Dr Renske van der Veen has led a research group in time-resolved X-ray spectroscopy and electron microscopy at HZB. Her research focuses on catalytic processes that enable, for example, the production of green hydrogen. She has now been appointed to a S-W2 professorship at the Institute of Optics and Atomic Physics (IOAP) at the Technische Universität Berlin.

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.

Dr. Artem Musiienko has earned a prestigious Maria Skłodowska Curie Postdoctoral Fellowship for his research project HyPerGreen. In the group of Prof. Antonio Abate, HZB, Musiienko will explore and improve lead-free perovskite solar cells with the goal to increase their efficiency to more than 20 %.  

The earthquake has struck Turkey and Syria in the heart, with large parts of the region destroyed to an unimaginable extent. We are dismayed by the extent of the destruction, the many victims and injured. The earthquake is causing inconceivable human suffering that we find difficult to comprehend. Our thoughts are with our colleagues who have family, friends, and acquaintances in the affected regions.

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.

Since 2016, accelerator physicist Ji-Gwang Hwang has been working at HZB in the department of storage rings and beam physics. He has made important contributions to beam diagnostics in several projects at HZB. He is now returning to his home country, South Korea, having accepted a professorship in physics at Gangneung-Wonju National University.

A team of scientists, led by researchers from the Max Born Institute in Berlin and Helmholtz-Zentrum Berlin in Germany and from Brookhaven National Laboratory and the Massachusetts Institute of Technology in the United States has developed a revolutionary new method for capturing high-resolution images of fluctuations in materials at the nanoscale using powerful X-ray sources. The technique, which they call Coherent Correlation Imaging (CCI), allows for the creation of sharp, detailed movies without damaging the sample by excessive radiation. By using an algorithm to detect patterns in underexposed images, CCI opens paths to previously inaccessible information. The team demonstrated CCI on samples made of thin magnetic layers, and their results have been published in Nature.

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.

Are you a doctoral researcher or Postdoc and your research has a strong link to (applied) data and information sciences?

Manfred Weiss, Sebastian Fiechter, Annette Pietzsch and Michael Tovar have been available to you as ombudspersons since 1 January 2023. They will be happy to advise you on all questions regarding good scientific practice at the HZB.

We are looking for young excellent scientists with leadership skills. Do you want to perform an innovative research project in one of HZB's research fields? Then apply by 20.02.2023!

A team of medical researchers at Charité has analyzed damage by focused high energetic X-rays in bone samples from fish and mammals at BESSY II. With a combination of microscopy techniques, the scientists could document the destruction of collagen fibres induced by electrons emitted from the mineral crystals. X-ray methods might impact bone samples when measured for a long time they conclude.

What keeps bones able to remodel themselves and stay healthy? A team from Charité Berlin has discovered clues to the key function of non-collagen protein compounds and how they help bone cells react to external load. The scientists used fish models to examine bone samples with and without bone cells to elucidate differences in microstructures and the incorporation of water. Using 3D neutron tomography at the Berlin research reactor BER II, they succeeded for the first time in precisely measuring the water diffusion across bone material - with a surprising result.

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.

We cordially invite you to read our new magazine "lichtblick". The time was ripe for a new format that can now be read comfortably on the screen. Take a look into the new issue!

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.

In order to transfer tandem solar cells from laboratory scale to production, HZB is cooperating with the solar module manufacturer Meyer Burger, which has great expertise in heterojunction technology (HJT) for silicon modules. Within the framework of this cooperation, mass production-ready silicon bottom cells based on heterojunction technology are to be combined with a top cell based on perovskite technology.

The 4000th structure is the molecule FKBP51, which is linked to stress-induced diseases such as depression, chronic pain and diabetes. The team led by Prof. Felix Hausch, TU Darmstadt, is using the knowledge of the three-dimensional structure to develop new strategies for the design of suitable drugs.

On Tuesday, 6 December 2022, Dr. Eike Köhnen received the Tiburtius Prize (First Place) for outstanding dissertations. Eike Köhnen has contributed to significantly increasing the efficiency of tandem solar cells made of perovskite and silicon, to the point of setting world records.

At the end of October 2022, the management appointed Ana Sofia Anselmo and Silvia Zerbe as new diversity officers. Together they will address diversity at HZB and drive it forward with employees. Ana works in the Director’s Office and is responsible for International Affairs. Silvia is deputy press spokesperson at HZB and is dedicated to internal communication at the centre.

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.

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.

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.

Would you like to spend a great summer in Berlin and gain unique experience in research? Then come and join us at HZB from 3 July to 25 August 2023! We invite students from all over the world to drive their own research project at HZB for eight weeks. Gain interesting insights and experience. We look forward to seeing you!

PEPPERONI, a four-year Research and Innovation project co-funded under Horizon Europe and jointly coordinated by Helmholtz-Zentrum Berlin and Qcells, will support Europe in reaching its renewable energy target of climate neutrality by 2050. The project will help advance perovskite/silicon tandem photovoltaics (PV) technology’s journey towards market introduction and mass manufacturing.

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.

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.

We mourn the loss of our former colleague Prof. Dr. Alexei Erko who passed away on the 22nd of October 2022 at the age of 70 after a short and severe illness.

How hydrogen ions or protons interact with their aqueous environment has great practical relevance, whether in fuel cell technology or in the life sciences. Now, a large international consortium at the X-ray source BESSY II has investigated this question experimentally in detail and discovered new phenomena. For example, the presence of a proton changes the electronic structure of the three innermost water molecules, but also has an effect via a long-range field on a hydrate shell of five other water molecules.

We mourn the loss of our former long-serving scientific director Prof. Dr. Michael Steiner who passed away on the 5th of November 2022 at the age of 79 in Berlin. He was a brilliant researcher to whom we owe a great deal.

Certain metal oxides are considered good candidates for photocatalysts to produce green hydrogen with sunlight. A Chinese team has now published exciting results on copper(I) oxide particles in Nature, to which a method developed at HZB contributed significantly. Transient surface photovoltage spectroscopy showed that positive charge carriers on surfaces are trapped by defects in the course of microseconds. The results provide clues to increase the efficiency of photocatalysts.

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.

The HZB is participating in the programme of Berlin Science Week and Falling Walls with a wide range of events. In this overview, we briefly summarise where you can find research from HZB and discuss it with scientists. Please note that you have to register for the events. Participation is free of charge.

Against a backdrop of the energy crisis, scientists and policymakers convened at Paul Scherrer Institute PSI in Switzerland and set out a vision for European accelerator based photon sources to address current and future societal challenges together.

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.

The Federal Minister for Education and Research, Bettina Stark-Watzinger, was in Berlin-Adlershof today to visit the Catalysis Laboratory (CatLab). CatLab is a research platform of Helmholtz-Zentrum Berlin and the Max Planck Society, dedicated to catalysis research that will deliver important innovations for achieving a green hydrogen economy. Upon her visit to the CatLab, the minister gained an insight into the latest technological advancements on producing and characterising thin-film catalysts and special methods for operando analytics and digital catalysis.

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.

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.

In the research consortium CARE-O-SENE, scientists are looking for more efficient ways to produce synthetic kerosene for use in aviation. We interviewed Tobias Sontheimer of HZB and Dirk Schär of the participating company Sasol about what has to be done, what obstacles there are, and how aviation can be decarbonised.

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.

The international research project CARE-O-SENE (Catalyst Research for Sustainable Kerosene) was granted 30 million euros in funding by the German Federal Ministry of Education and Research (BMBF). Additionally, the industrial consortium partners contribute 10 million euros. The aim of the project is to develop novel, next-generation Fischer-Tropsch catalysts and thus to optimise the production of sustainable kerosene – or Sustainable Aviation Fuel (SAF) – on an industrial scale. Helmholtz-Zentrum Berlin (HZB) is part of this collaboration.

Rutger Schlatmann is a solar expert from the Helmholtz-Zentrum Berlin (HZB) and professor at the Berlin University of Applied Sciences. At the HZB he heads the Competence Centre for Photovoltaics, which successfully brings together solar research and industry. Now the expert has been elected as chairman of the European Technology and Innovation Platform for Photovoltaics (ETIP PV). It provides independent advice on energy policy issues and the expansion of photovoltaics in Europe.

At HZB, a laboratory for automated X-ray tomography on solid-state batteries is being set up. The special feature: 3D data during charge/discharge processes (operando) can be evaluated quickly and in a more versatile way using artificial intelligence (AI) methods. The Federal Ministry of Research and Education is funding the "TomoFestBattLab" project with 1.86 million euros.

Let's assume there are solar systems on every roof. And what happens if the sun doesn't shine for a while? Follow the thought experiment of the Tagesschau Podcast. Our solar expert and architect Thorsten Kühn joins us.

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.

The non-university research institutions in Berlin will work even more closely together in the future. Their association Berlin Research 50 (BR50), founded in 2020, has joined forces to form a registered non-profit association on 4. October 2022. Together, the research institutions want to further develop and strengthen Berlin as a science location.

Auf dem Programm stehen ein Rundgang durch das Reallabor des Helmholtz-Zentrum Berlin gefolgt von Fachvorträgen sowie einem Austausch mit Experten*innen vor Ort.

Neutron scattering is considered the method of choice for investigating magnetic structures and excitations in quantum materials. Now, for the first time, the evaluation of measurement data from the 2000s with new methods has provided much deeper insights into a model system – the 1D Heisenberg spin chains. A new toolbox is available for elucidating future quantum materials has been achieved.

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.

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.

The Highlight Report 2021 presents compact information on important developments at HZB and a selection of the scientific results published in renowned journals.

Press release _ Berlin, 14 September: For decades, science in Berlin has been an important driver of innovation and progress. Creative, talented people from all over the world come together here and develop new ideas from which we all benefit as a society. Many discoveries – from fundamental insights to marketable products – are made by doing research with synchrotron light. Researchers have had access to this intense light in Berlin for 40 years. It inspires many scientific disciplines and is an advantage for Germany.

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.

Around 400 scientists exchanged ideas at the German Conference for Research with Synchrotron Radiation, Neutrons and Ion Beams at Large Facilities (SNI2022), which took place in Berlin from 05-07 September 2022. Helmholtz-Zentrum Berlin (HZB) was the organiser of the conference. The Committee Research with Neutrons (KFN) awarded prizes to two young scientists. The prizes went to Dr Navid Qureshi (Institut Laue-Langevin, ILL, France) and Artur Glavic (Paul Scherrer Institute, PSI, Switzerland).

50 issues of lichtblick have been published since 2009 and that inspired us to do something special. In this issue, we focus on employees who do a great voluntary work or have an exciting hobby. They represent the many, many people who make HZB an vibrant and diverse place.

On 1 September, HZB welcomed 15 new employees who are starting an apprenticeship, a dual study programme or a voluntary year at HZB. At an introductory event at the Wannsee site, HZB's Administrative Director Thomas Frederking welcomed the new employees and wished them a good start at the research centre.

Felix Büttner has led a junior research group at HZB. Now he has accepted a call to the University of Augsburg. As head of a joint research group, he will continue his studies of magnetic skyrmions at BESSY II.

On 30 August, BESSY II ligth source will resume user operation: the research centre will then welcome guest researchers from all over the world and support them in their various experiments. The 14-week  shutdown was the longest in BESSY II history. Among other works, the main supply was completely renewed. The successful completion of the work was celebrated with all those involved.

Wie umgehen mit begrenztem Platz? Städte und Kommunen müssen sich jetzt auf die Folgen des Klimawandels vorbereiten. Gründächer, begrünte Fassaden und großflächige Entsiegelungen könnten zu einem besseren Mikroklima beitragen. Aber wird der Platz nicht auch für Photovoltaik benötigt?

In einem kontroversen Gespräch loten die Experten Björn Rau (HZB, BAIP) und Jens Hasse (Deutsches Institut für Urbanistik) die Optionen aus und finden neue Lösungen.

Alexander Gray from Temple University in Philadelphia, USA, is working with HZB physicist Florian Kronast to investigate novel 2D quantum materials at BESSY II. With the fellowship from the Alexander von Humboldt Foundation, he can now deepen this cooperation. At BESSY II, he wants to further develop depth-resolved X-ray microscopic and spectroscopic methods in order to investigate 2D quantum materials and devices for new information technologies even more thoroughly.

Electrical energy from wind or sun can be stored as chemical energy in hydrogen, an excellent fuel and energy carrier. The prerequisite for this, however, is efficient electrolysis of water with inexpensive catalysts. For the oxygen evolution reaction at the anode, nanostructured nickel silicide now promises a significant increase in efficiency. This was demonstrated by a group from the HZB, Technical University of Berlin and the Freie Universität Berlin as part of the CatLab research platform with measurements among others at BESSY II.

Dr. Michelle Browne establishes her own young investigator group at the HZB . Starting in August, the group is co-funded by the Helmholtz Association for the next five years. The electrochemist from Ireland concentrates on electrolytically active novel material systems and wants to develop next-generation electrocatalysts, for example hydrogen production. At HZB she will find the perfect environment to conduct her research.

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.

Industrial processes always produce fine-grained residues. These rarely find their way back into the industrial value chain, but are usually disposed of and represent a potential environmental risk. The FINEST project records and investigates various of these fine-grained material flows with the aim of developing new concepts to keep them in the cycle and safely dispose of remaining residues. 
FINEST was successful in the Helmholtz Association's sustainability competition and will now receive 5 million euros in funding. 

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.

Solar photovoltaics is a reliable and sustainable way to generate energy. A study has evaluated for the first time the lifecycle environmental impact of industrially produced perovskite-on-silicon tandem solar modules, provided by Oxford PV. The conclusion: these innovative tandem solar modules are even more environmentally friendly than conventional silicon heterojunction modules over their lifetimes. The study has now been published by the peer reviewed journal Sustainable Energy & Fuels.

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.

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. 

A cheerful mood prevailed last Saturday, 2 July 2022: After two years of online format due to the Corona pandemic, the event could finally take place on site again. This time, HZB opened its doors at the Adlershof site and invited people to take tours of BESSY II and visit the Energy Street. Almost 2700 people came to HZB and had a good time until midnight.  

Important info: At the HZB, FFP2 masks are mandatory indoors from the age of 14 during this event.

How can solar cells be produced even more efficiently? Why is "green" hydrogen so important for our future? Why does Berlin need an accelerator to screen materials? The answers are available at the Long Night of the Sciences. On July 2, 2022, 5 p.m. to midnight, HZB opens its doors at the Adlershof site and invites young and old to experiment.

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.

The Werner-von-Siemens-Ring Foundation has accepted Prof. Dr. Olga Kasian into its network in recognition of her outstanding scientific achievements. Olga Kasian heads a junior research group on electrocatalysis at HZB and is a professor at the University of Erlangen-Nürnberg (FAU). The foundation has been honoring young researchers in the technical and natural sciences since 1977 and offers them unique opportunities for interdisciplinary networking.

On Friday, 17 June, a delegation from Singapore visited HZB. Heng Swee Keat, Deputy Prime Minister of Singapore, was accompanied by the Ambassador to Singapore in Germany, Laurence Bay, as well as representatives from research and industry.

HESEB extends research possibilities to soft X-rays

A new experimental station has been opened at the X-ray source SESAME in Jordan: HESEB, the Helmholtz-SESAME Beamline, has been designed by five research centres of the Helmholtz Association under the leadership of DESY. It considerably expands the experimental possibilities of the facility.

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.

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.

People from many different countries work at the Helmholtz-Zentrum Berlin and enrich our atmosphere. For our cookbook, employees and guest researchers from six continents have contributed their favorite recipes.

Ronen Gottesman has been a scientist at the HZB Institute for Solar Fuels for the past five years, establishing the pulsed laser deposition team and developing novel complex metal-oxide semiconducting lightabsorbers for photoelectrochemical water splitting to produce "green" hydrogen. Now he is following a call to the Institute of Chemistry at the Hebrew University of Jerusalem in Israel (HUJI), where he will lead his own research group. 

Zinc deficiency is a global health problem affecting many people and results in a weak immune system in adults and especially in children. This is a challenge for health systems and is quite evident in the Mexican population, for example. Seeking explanations, researchers in Mexico teamed up with international synchrotron experts and gained new insights from studying Drosophila fruit flies, which are known to be a decent model system for human zinc metabolism.
Thanks to beamtime at BESSY II and at the SLS (PSI), they were able to show that the zinc stores in Drosophila flies depend on the tryptophan content of their diet.

JOHANNESBURG, SOUTH AFRICA – 24 May 2022: CARE-O-SENE research project will develop advanced catalysts for sustainable aviation fuels

The company Sasol and Helmholtz-Zentrum Berlin (HZB) will lead a consortium to develop and optimise next-generation catalysts that will play a key role in decarbonising the aviation sector through sustainable aviation fuels (SAF).

The X-ray source BESSY II is in a three-month period of shutdown. During this period, the low voltage main distribution panel in the supply building outside the electron storage ring is being renovated. This will secure the long-term operation of BESSY II over the next decade.

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 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.

On 16 May 2022, HZB received a delegation from the Brazilian Ministry of Science, Technology and Innovation (MCTI). Vice-Minister of Science Sergio Freitas de Almeida was visibly impressed by the many research activities being done at HZB to drive the transition to a climate-neutral energy supply in society forward.

On 13 May, three research centres of the Helmholtz Association - DESY, HZDR and HZB - presented their joint strategy for accelerator-based light sources to German MPs.

King Carl XVI Gustaf of Sweden as well as a group of business leaders from large corporations such as Ericsson, Nordholt, Vattenfall, ABB, Schneider Electric and Swedish representatives from the public sector and academia visited the Adlershof Technology Park on 11 May 2022.

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.

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.

For 75 years, synchrotron radiation sources have been indispensable for gaining knowledge. Antje Vollmer talks about international networking, a new record at the X-ray source BESSY II – and how she can tell from the research applications alone which social problems are particularly pressing at the moment.

Professor Alexei Gruverman was granted a Humboldt Research Award in October 2020.  Due to the COVID pandemic, he could not travel until this year. For a few months he is now hosted by Helmholtz-Zentrum Berlin at the Institute “Functional oxides for energy efficient information technology”. 

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.

Climate change has Amran Al-Ashouri concerned. As a physicist, he knows how urgently and quickly measures need to be taken to limit the global temperature increase to between 1.5 and 2 degrees Celsius. In his private life, the 29-year-old scientist is accordingly a member of the association “climactivity”, which aims to educate as many people as possible about important matters in climate protection.

The 5th Conference for Research with Synchrotron Radiation, Neutrons and Ion Beams at Large Facilities takes place form 5 - 7 September 2022 in Berlin. In response to a great demand the deadline for the abstract submission to the SNI2022 conference has been extended to 1 May. Take this opportunity and submit your abstract by Sunday!

In der neuen Ausgabe der lichtblick stellen wir Renske van der Veen in der Titelgeschichte vor. Sie ist seit Sommer 2021 am HZB und baut eine neue Forschungsgruppe auf. Warum sie aus den USA nach Deutschland gekommen ist und wo die kulturellen Unterschiede liegen, erzählt sie darin.

A team at the Max Planck Institute of Colloids and Interfaces (MPICI) has discovered with help of BESSY II new properties of collagen: During the intercalation of minerals in collagen fibers, a contraction tension is generated that is hundreds of times stronger than muscle strength. The associated changes in the collagen structure were observed using X-ray diffraction at the BESSY II synchrotron in Berlin-Adlershof while mineralization was taking place.

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.

Physicists know about the huge chasm between quantum physics and the theory of gravity. However, in recent decades, theoretical physics has provided some plausible conjecture to bridge this gap and to describe the behaviour of complex quantum many-body systems, for example black holes and wormholes in the universe. Now, a theory group at Freie Universität Berlin and HZB, together with Harvard University, USA, has proven a mathematical conjecture about the behaviour of complexity in such systems, increasing the viability of this bridge. The work is published in Nature Physics.

Photoacids are molecules that release a proton upon electronic excitation, thus enhancing the acidity of a liquid. Pioneering work by Theodor Förster has shown the direct relationship between the wavelength position of optical absorption and acidity properties with which the increase in acidity  in the first electronic excited state can be quantified. However, underlying full microscopic explanations for the photoacidity phenomenon have remained sparse. With ultrafast X-ray spectroscopy, locally probing the electronic structure of a proton donating group of an amine aromatic photoacid has now provided direct insight in the changes of electronic structure. The long standing open question for photoacidity has now finally been resolved: major electronic structure changes occur on the base side of the so-called Förster cycle, whereas the acid side plays a minor role. 

It is with great dismay that we are witnessing Russia’s military attack on Ukraine, launched on 24 February 2022. We condemn this grave breach of international law. We are concerned for all the inhabitants of Ukraine and in particular for the researchers and students affected by the war. They have our unconditional solidarity.

An international cooperation has analysed samples of NdBi crystals which display interesting magnetic properties. In their experiments including measurements at BESSY II they could find evidence for so called Fermi arcs in the antiferromagnetic state of the sample at low temperatures. This observation is not yet explained by existing theoretical ideas and opens up exciting possibilities to make use of these kind of materials for innovative information technologies based on the electron spin rather than the charge.

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.

HZB is an employer that comprehensively strengthens and cares for the diversity of its employees. HZB publicly acknowledges this by signing the Diversity Charter. The charter is run by an association that works to anchor diversity in the working world.

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.

The BAIP consulting office for building-integrated photovoltaics has been launched as a knowledge transfer project in 2019, funded by the Helmholtz Association's Initiative and Networking Fund. In order to build a bridge between the world of construction and photovoltaics, the consulting office provides comprehensive knowledge for architects, planners, builder-owners, investors and urban developers. After an excellent evaluation, the BAIP consulting office will be permanently financed by HZB.

Dr. Katarzyna Siewierska joins the group of Prof. Alexander Föhlisch as a postdoctoral Humboldt Research fellow. She has earned her PhD at Trinity College in Dublin, Ireland, and plans in the next two years to explore the electronic structure and spin dynamics of half-metallic thin films at BESSY II.  Understanding these spintronic materials better may pave the way for more energy efficient data storage technologies.

Q CELLS and Helmholtz-Zentrum Berlin achieve a new world record efficiency for a 2-terminal tandem solar cell combining a mass-production ready silicon bottom cell based on Q.ANTUM technology and a top-cell based on perovskite technology. The efficiency is 28.7%.

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.  

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.

2021 was not an easy year for international research: owing to lockdowns and travel bans, science was hit hard by the pandemic situation. Nevertheless, experiments continued at a high level at the BESSY II light source in Berlin Adlershof – thanks in part to new remote service offers. Here are the figures at a glance.

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.

On February 17, 2022, the Adlershof Dissertation Prize was awarded for the 20th time. Dr. Amran Al-Ashouri (3rd from right) from the HZB young investigator research group "Perovskite tandem solar cells" received the prize endowed with 3,000 euros. The physicist is researching how new organic contact layers can be used to optimize highly efficient perovskite silicon tandem solar cells.

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.

To support the development of young scientists at HZB in the best possible way - this has been a long-standing goal of the HZB. Now this task will be pursued even more strategically. To this end, the new board “HZB Succeed” has been founded in January 2022.

Eva Unger was now appointed as W2 professor at Humboldt-Universität zu Berlin. Prof. Dr. Eva Unger leads a research group at HZB. She develops scalable technologies for the production of perovskite semiconductors for low-cost and highly efficient solar cells.

Most bacteria have the ability to form communities, biofilms, that adhere to a wide variety of surfaces and are difficult to remove. This can lead to major problems, for example in hospitals or in the food industry. Now, an international team led by Hebrew University, Jerusalem, and the Technical University Dresden, has studied a model system for biofilms at the synchrotron radiation facilities BESSY II at HZB and the ESRF and found out what role the structures within the biofilm play in the distribution of nutrients and water.

Electron paramagnetic resonance (THz-EPR) at BESSY II provides important information on the electronic structure of novel magnetic materials and catalysts. In mid-January 2022, the researchers brought a new, superconducting 12-T magnet into operation at this end station, which promises new scientific insights.