New instrument at BESSY II: The OÆSE endstation in EMIL
The new end station was set up in the EMIL laboratory. © R. Garcia-Diez /HZB
Scheme of the endstation, including the sample environment, the analysis chamber and the operando beamline section. © HZB
A new instrument is now available at BESSY II for investigating catalyst materials, battery electrodes and other energy devices under operating conditions: the Operando Absorption and Emission Spectroscopy on EMIL (OÆSE) endstation in the Energy Materials In-situ Laboratory Berlin (EMIL). A team led by Raul Garcia-Diez and Marcus Bär showcases the instrument’s capabilities via a proof-of-concept study on electrodeposited copper.
Solar cells, catalysts, and batteries are composed of so-called energy materials, i.e., materials that either convert or store energy. Their functionality is based on complex chemical or physical processes. In order to improve their functionality, it is crucially required to understand those processes, ideally while they are taking place, i.e. by in situ and operando studies. A new experimental station enabling corresponding experiments is now available at the Energy Materials In-situ Laboratory Berlin (EMIL) located at the synchrotron facility BESSY II.
The “Operando Absorption and Emission Spectroscopy on EMIL” (OÆSE) provides detailed insights into the electronic and chemical structures of materials and interfaces and their changes during critical (electro)chemical processes via X-ray absorption (XAS) and emission (XES) spectroscopy .
At the heart of the OÆSE endstation is a modular and flexible in situ/operando sample environment, specially tailored to tackle the specific research questions required for each energy material, which design ensures easy adaptation to different experiments.
To demonstrate the capabilities of the OÆSE endstation, the team led by Raul Garcia-Diez and Marcus Bär studied in situ the electrochemical deposition of copper from an aqueous CuSO4 electrolyte using combined soft and hard X-ray absorption spectroscopy exploiting the two-color beamline of EMIL. The case study shows that the new endstation offers valuable insights into dynamic electrochemical processes and thus enables a better understanding of complex electrochemical systems.
- Long-term stability for perovskite solar cells: a big step forwardPerovskite solar cells are inexpensive to produce and generate a high amount of electric power per surface area. However, they are not yet stable enough, losing efficiency more rapidly than the silicon market standard. Now, an international team led by Prof. Dr. Antonio Abate has dramatically increased their stability by applying a novel coating to the interface between the surface of the perovskite and the top contact layer. This has even boosted efficiency to almost 27%, which represents the state-of-the-art. After 1,200 hours of continuous operation under standard illumination, no decrease in efficiency was observed. The study involved research teams from China, Italy, Switzerland and Germany and has been published in Nature Photonics.
- Energy of charge carrier pairs in cuprate compoundsHigh-temperature superconductivity is still not fully understood. Now, an international research team at BESSY II has measured the energy of charge carrier pairs in undoped La₂CuO₄. Their findings revealed that the interaction energies within the potentially superconducting copper oxide layers are significantly lower than those in the insulating lanthanum oxide layers. These results contribute to a better understanding of high-temperature superconductivity and could also be relevant for research into other functional materials.
- Electrocatalysis with dual functionality – an overviewHybrid electrocatalysts can produce green hydrogen, for example, and valuable organic compounds simultaneously. This promises economically viable applications. However, the complex catalytic reactions involved in producing organic compounds are not yet fully understood. Modern X-ray methods at synchrotron sources such as BESSY II, enable catalyst materials and the reactions occurring on their surfaces to be analysed in real time, in situ and under real operating conditions. This provides insights that can be used for targeted optimisation. A team has now published an overview of the current state of knowledge in Nature Reviews Chemistry.