Berlin 2018 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 27: Nitrides: Preparation and characterization II

HL 27.2: Vortrag

Mittwoch, 14. März 2018, 09:45–10:00, EW 203

Photoelectrochemical response of GaN, InGaN and GaNP nanowire ensembles — •Jan M. Philipps¹, Rene Couturier¹, Sara Hölzel², Pascal Hille², Jörg Schörmann¹, Irina A. Buyanova³, Sangam Chatterjee¹, Martin Eickhoff², and Detlev M. Hofmann¹ — ¹Institute of Experimental Physics I, Justus Liebig University Giessen, 35392 Giessen, Germany — ²Institute of Solid State Physics, University of Bremen, 28359 Bremen, Germany — ³Department of Physics, Chemistry and Biology, Linköping University, S-581 83 Linköping, Sweden

The photoelectrochemical responses of GaN, GaNP and InGaN nanowire ensembles are investigated by electrical bias dependent photoluminescence, photocurrent and spin trapping experiments. The results are explained in the frame of the surface band bending model. The model is sufficient for InGaN nanowires, but for GaN nanowires electrochemical etching processes in the anodic regime have to be considered additionally. These processes affect the nanowire shape and lead to oxygen rich surface (Ga_xO_y) conditions as evident from transmission electron microscopy and the analysis of energy dispersive X-ray fluorescence. For the GaNP nanowires a bias dependence of the carrier transfer to the electrolyte is not reflected in the photoluminescence response, which is tentatively ascribed to a different origin of radiative recombination in this material as compared with (In)GaN. The corresponding consequences for the applications of the materials for water splitting or pH-sensing will be discussed.