Dresden 2026 – scientific programme
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DS: Fachverband Dünne Schichten
DS 8: Transport Properties
DS 8.1: Talk
Tuesday, March 10, 2026, 14:00–14:15, REC/B214
Polaron Transport in BiVO4 — •Nils Sekinger1,2, Tsedenia Zwedie1,2, and Ian Sharp1,2 — 1Walter Schottky Institute, Technical University Munich — 2Physics Department, TUM School of Natural Sciences, Technical University of Munich
Bismuth vanadate (BiVO4) has received considerable attention as a potential photoanode for photocatalytic applications, thanks to its moderate bandgap of ∼2.5 eV and favourable band edge energetics. However, it is believed that photogenerated electrons localise at vanadium sites to form small polarons, while holes localise around BiO8 units to form large polarons, thereby inhibiting their transport [1]. This study investigates charge transport in monoclinic BiVO4 using temperature-dependent photoconductivity measurements. Under illumination, we observe two distinct thermally-activated transport regimes. With decreasing temperature, the large-barrier electron hopping transport characteristic transitions to a lower barrier regime that may arise from the freeze-out of electron transport, resulting in a dominant influence from minority holes. The transport barriers, hopping distances, and effective masses of both small and large polarons in the dark and with illumination at different intensities are investigated. Analysing the dependence of the resistivity on temperature and light intensity provides critical insights into the polaronic conduction mechanism and offers experimental validation for theoretical models describing polaron transport. These findings improve our understanding of charge transport in BiVO4 and its use in photocatalytic and electrochemical applications.
[1] Wiktor et al. ACS Energy Lett. 2018, 3(7), 1693-1697
Keywords: Bismuth Vanadate; Polarons; Temperature-dependent Photoconductivity