HZB Newsroom

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.

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.

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.

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.

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.

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!

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.

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.

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.

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.

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.

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.

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.