Persistent optical phenomena in oxide semiconductors
ORAL · Invited
Abstract
The interaction of transparent oxide semiconductors with light is a central issue for a range of applications. We discovered large, room-temperature persistent photoconductivity (PPC) in potassium tantalate (KTaO3) after annealing in a hydrogen atmosphere [1]. The conductivity increases by four orders of magnitude after exposure to UV light, which persists for years after the light is turned off. Photochromism, due to a defect absorption peak, appears and is beyond persistent – it actually grows in the dark! Photochromism has also been found in Cu-doped gallium oxide (β-Ga2O3:Cu) [2]. Hydrogen impurities are key actors in these phenomena.
*National Science Foundation (NSF) under Grant No. DMR-2335744
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Publication: [1] M.M. Santillan, I. Chatratin, A. Janotti, and M.D. McCluskey, Room temperature persistent photoconductivity of KTaO3 single crystals, Phys. Rev. Materials 8, L111601:1-5 (2024).
[2] J. Jesenovec, C. Pansegrau, M.D. McCluskey, J.S. McCloy, T.D. Gustafson, L.E. Halliburton, and J.B. Varley, Persistent room temperature photodarkening in Cu-doped β-Ga2O3, Phys. Rev. Lett. 128, 077402:1-6 (2022).
Presenters
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Matthew Douglas McCluskey
- Washington State University