Dresden 2017 – scientific programme

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O: Fachverband Oberflächenphysik

O 84: Focus Session: Semiconductor Materials and Nanostructure for Photocatalysis

O 84.5: Talk

Thursday, March 23, 2017, 11:30–11:45, POT 51

Photo-catalytic carbon dioxide reduction with InGaN photo-electrodes — •Viktoria Kunzelmann, Andreas Zeidler, Andrea Winnerl, and Martin Stutzmann — Walter Schottky Institut, Technische Universität München, Garching, Deutschland

Carbon dioxide (CO₂) has reached a critical level in atmosphere and counts as one of the reasons for global warming. Reducing this greenhouse gas to hydrocarbon fuels would help solving environmental issues and simultaneously address challenges such as energy storage and resource shortage. Using a photo-catalytic reaction to convert CO₂ into fuels is one way to address this issue. Due to the chemical inertness of CO₂ and the instability of suitable catalysts, efficient CO₂ reduction is still challenging. Using gallium nitride (GaN) as a photo-electrode is promising, since GaN is relatively stable under operating conditions and provides electrons with sufficient energy. Tuning the band gap by alloying GaN with indium might additionally enhance desired reduction processes. The current work concerns charge transfer processes on the interface of p- and n-type GaN or indium gallium nitride (InGaN), grown by molecular beam epitaxy, and an electrolyte. The characterization of the photo-electrode material is done by: atomic force and scanning electron microscopy for topography analysis, Kelvin probe force microscopy to analyze the surface potential landscape of the samples, surface photo-voltage measurements to evaluate the change of the electronic band structure due to illumination and Hall effect measurements to clarify the charge charrier density. Additionally, first results of photoelectrochemical measurements will be presented.