Regensburg 2022 – wissenschaftliches Programm
KFM 21.7: Vortrag
Mittwoch, 7. September 2022, 17:00–17:15, H36
Exploring Zirconium-doped Tantalum Nitride as a Photoanode for Solar Energy Conversion — •Oliver Brune, Laura I. Wagner, Verena Streibel, and Ian D. Sharp — Walter Schottky Institut and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
Solar water splitting could pave the way to carbon-free hydrogen production as it allows for direct transformation of sunlight into chemical energy. While the oxygen evolution reaction is a crucial step in generating green hydrogen, there remains a lack of semiconductor photoanode materials that can simultaneously fulfill three key requirements: long-term chemical stability, high photocarrier extraction efficiencies, and appropriate bandgap for harvesting solar radiation. Nevertheless, among the various materials that have been investigated, the transition metal nitride Ta3N5 offers significant promise as an efficient n-type photoanode. Building upon this established material, we use reactive co-sputtering and subsequent ammonia annealing to introduce Zr into Ta3N5, with the aim of investigating how the ternary nitride character of Zr-Ta-N(O) enables tuning of key semiconductor properties. Using a range of complementary characterization methods, we show that synthesis parameters and Zr content have a significant influence on the crystal structure, morphology, and optoelectronic properties of this ternary compound. Based on these insights, we optimize the composition and synthesis processes to achieve a highly stable and efficient photoanode material, which is a key requirement for solar water splitting.