SKM 2021 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 11: Focus Session: Functional Metal Oxides for Novel Applications and Devices
HL 11.2: Hauptvortrag
Dienstag, 28. September 2021, 14:00–14:30, H4
Ultrathin oxides on InGaN nanowires: Hybrid nanostructure photoelectrodes and optical analysis of chemical processes — P. Neuderth2, J. Schörmann2, M. Coll3, M. de la Mata4, J. Arbiol4, R. Marschall5,6, and •M. Eickhoff1,2 — 1Inst. of Solid State Physics, Univ. of Bremen, Germany — 2Inst. of Exp. Phys. I, JLU Giessen, Germany — 3Inst. de Ciencia de Materials de Barcelona, Spain — 4ICN2, Barcelona, CAT, Spain — 5Inst. of Phys. Chem., JLU Giessen, Germany — 6Phys. Chem. III, Univ. of Bayreuth, Germany
We demonstrate an experimental strategy for systematically assessing the influence of surface passivation layers on the photocatalytic properties of nanowire (NW) photoanodes by combining photocurrent analysis, photoluminescence spectroscopy and high resolution transmission electron microscopy. We apply this approach to separate the influence of different mechanisms on recombination and transport processes of photogenerated carriers and to compare the effect of TiO2, CeO2 and Al2O3 coatings deposited by atomic layer deposition (ALD). Due to efficient charge transfer from the InGaN NW core a stable TiO2-covered photoanode with visible light excitation is realized. As further applications we demonstrate the quantitative optical analysis of oxygen diffusion in ultrathin CeO2 and of the Li intercalation in TiO2 using hybrid nanostructures. In both cases the optical properties of the InGaN NWs are used as a probe for chemical processes in the ultrathin oxide layer that was deposited by ALD. Further potential applications of advanced hybrid nanostructures are discussed.