TUM School of Natural Sciences
Walter Schottky Institute - Chair of Experimental Semiconductor Physics
Prof. Dr. Ian Sharp
The Chair for Experimental Semiconductor Physics at TUM works to design and develop advanced semiconducting materials and functional interfaces, with a focus on thin films and their heterostructures for conversion of sunlight to chemical fuels, including via solar water splitting. Through this research, the group aims to uncover and direct optical excitations, charge carrier transport mechanisms, and interfacial dynamics.
To gain new insights into these fundamental processes, we combine advanced deposition methods, including reactive sputtering, atomic layer deposition, and molecular beam epitaxy, with a comprehensive suite of (in situ) structural, elemental, and optoelectronic characterization tools. This integrated approach enables us to interrogate and control complex light-to-charge and charge-to-chemical transformation pathways that underlie the functional characteristics of solar-to-hydrogen conversion systems.
Website: Research at WSI
Contact: Dr. Verena Streibel
Development of direct solar water splitting demonstrators
The H2Demo project aims to develop the first large-scale demonstrators for direct solar hydrogen production with high conversion efficiency. In this approach, a catalyst-coated semiconductor structure is immersed into an aqueous electrolyte, absorbs sunlight, and generates a sufficiently high photovoltage to split water into hydrogen and oxygen directly on the surface.
The H2Demo project focuses on the development of highly efficient, cost-effective and scalable demonstrators. To this end, novel GaAsP/Si tandem absorbers are optimised for water splitting, and multifunctional protective layers are developed that simultaneously protect against corrosion and serve as catalysts for the hydrogen and oxygen production. Atomic layer deposition allows nanoscale effects in the protective layers to be specifically utilised in order to combine high catalytic activity with minimal parasitic absorption. TUM participates in this large collaboration project, which is led by the Fraunhofer Institute for Solar Energy Systems, by developing stable and efficient interfaces between the light absorber, catalyst, and liquid electrolyte.
Type: BMBF Research Project
Funding: German Federal Ministry of Education and Research (BMBF)
Funding code: 03SF0619J
Runtime: 04/2021-04/2027
Website: H2Demo
Contact: https://www.professoren.tum.de/sharp-ian
Coupling of novel photoelectrode materials to selective catalyst systems for artificial photosynthesis
The CO2UPLED project is developing novel materials that use sunlight to convert water and CO2 into solar fuels. While the conversion of sunlight into electricity has been well researched, there are currently no efficient methods for producing solar fuels directly. CO2UPLED aims to close this gap.
At the heart of CO2UPLED are novel oxynitride thin films made of metal cations, oxygen and nitrogen. By selectively varying the cation mixture and the nitrogen-to-oxygen ratio, oxynitrides can be specifically adapted to efficiently absorb sunlight. The photoelectrodes are coupled with catalysts to accelerate chemical reactions. The CO2UPLED team uses statistical methods to optimize the synthesis processes and ensure consistent, high-quality material production. Advanced spectroscopic techniques such as near-ambient pressure X-ray spectroscopy and time-resolved infrared spectroscopy enable a detailed analysis of interfacial processes. These investigations aim to enhance charge separation and transfer, increase the stability of materials used, and improve the efficiency of sunlight-driven conversion of water and CO2 into fuels.
Type: BMBF Junior Research Group
Funding: German Federal Ministry of Education and Research (BMBF)
Funding code: 033RC034
Runtime: 02/2024-01/2030
Website: SINATRA - CO2UPLED
Contact: Verena Streibel
Further Information: SINATRA Research Initiative