Regensburg 2013 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 91: Poster Session: Quantum dots and wires: preparation & characterization & optical properties & transport properties
HL 91.9: Poster
Thursday, March 14, 2013, 16:00–20:00, Poster A
Radical formation by photo-generated carriers at GaN nanowires - electrolyte interfaces — •Jan Martin Philipps, Gesche Mareike Müntze, Pascal Hille, Jörg Schörmann, Jörg Teubert, Detlev Michael Hofmann, and Martin Eickhoff — I. Physikalisches Institut, JLU Giessen, Germany
We investigated the transfer of photogenerated carriers from GaN nanowires into an electrolyte environment by electron paramagnetic resonance (EPR) and fluorescence-spectroscopy. Using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap and a neutral electrolyte (pH = 7) the formation of hydroxide radicals dominates, while for an electrolyte with a pH of 13.5 the superoxide formation becomes detectable. We explain this asymmetry for the two processes in the frame of the surface band bending model considering the redox potentials in the electrolyte and the conduction and valence band positions of the semiconductor.