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.
- Detailed insights at BESSY II into the oxidation processes of copperBefore pure copper oxide builds up, complex superstructures such as ‘29’CuxO, are formed. The new results on the '29' CuxO superstructure have relevance for catalyst research and corrosion protection in the development of safe copper containers for nuclear waste repositories.
- BESSY II: Evaporated perovskites in tandem solar cells improvedPerovskite-silicon tandem solar cells achieve significantly higher efficiencies than silicon solar cells on their own. One particularly attractive method is co-evaporation of the perovskite precursor molecules on top of the silicon subcell. Scientists at HZB have analysed film growth on the nanoscale at BESSY II and found a new way to improve the quality of the perovskite layer: adding a thin seed layer of caesium chloride between the two sub-cells promotes uniform perovskite growth and suppresses the formation of undesired lead iodide at the interface.
- An important step towards detecting fractons in quantum spin liquidsFollowing predictions of the existence of fractons in quantum spin liquids by more general gauge field theories, researchers at HZB succeeded in detecting these quasi-particles also in a quantum solid-state model.