Dresden 2026 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 42: Nitrides III – Emerging thin films and electrochemistry
HL 42.1: Hauptvortrag
Donnerstag, 12. März 2026, 11:15–11:45, POT/0006
Transition Metal Nitride Semiconductors for Photoelectrochemical Energy Conversion — •Verena Streibel1,2, Laura I. Wagner1,2, Elise Sirotti1,2, David A. Egger2, and Ian D. Sharp1,2 — 1Walter Schottky Institute, Technical University of Munich, Garching, Germany — 2Physics Department, TUM School of Natural Sciences, Technical University of Munich, Garching, Germany
Transition metal nitride thin films are emerging as promising materials for (photo)electrochemical applications. However, their synthesis and defect control remain challenging. Here, we use reactive co-sputtering to synthesize and engineer nitride thin films with precise control over composition and doping in the Ti-Ta-N,1 Zr-Ta-N,2,3 and Hf-Ta-N materials space. Starting from orthorhombic Ta3N5, we show that substitutional Ti doping improves photoconversion efficiency by modulating defects and recombination dynamics. While high Ti doping forms a secondary TiN phase, Zr and Hf yield tunable solid solutions in the Zr-Ta-N-(O) and Hf-Ta-N-(O) systems, exhibiting bandgap modulation and large refractive indices. Notably, a new bixbyite-type ternary compound, ZrTaN3, forms at a 1:1 Zr:Ta ratio, showing strong visible light absorption and photoanodic activity. DFT calculations reveal a tunable direct bandgap driven by cation ordering.3 Our findings establish composition engineering as a key strategy for tailoring band structure and charge transport in emerging nitride semiconductors.
[1] Wagner, L.I. et al., Adv. Funct. Mater. 2024, 34, 2306539.
[2] Wagner, L.I. et al., Adv. Mater. Interfaces 2025, 12, 2400745.
[3] Sirotti, E. et al., Adv. Energy Mater. 2024, 202402540.
Keywords: Photoelectrochemistry; Thin Films; Reactive Sputtering; Cation Ordering; Photoanodes