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HL: Fachverband Halbleiterphysik
HL 62: Gallium Nitride: Optical and Electronic Properties
HL 62.10: Talk
Wednesday, March 9, 2016, 17:30–17:45, H17
InGaN/GaN nanowire heterostructures for multifunctional optochemical sensor systems — •Sara Lippert1, Marc Riedel2, Christian Dern1, Jens Wallys1, Ervice Pouokam3, Pascal Hille1, Jörg Teubert1, Fred Lisdat2, Martin Diener3, and Martin Eickhoff1 — 1I. Physical Institute, Justus-Liebig-University, Gießen, Germany — 2Biosystems Technology, Institute of Applied Life Sciences, Technical University of Applied Sciences, Wildau, Germany — 3Institute for Veterinary Physiology and Biochemistry, Justus-Liebig-University, Gießen, Germany
InGaN/GaN nanowire heterostructures as nanophotonic probes are presented for the detection and monitoring of biochemical processes in electrolytes. By incorporation of Indium the excitation wavelength was shifted to the visible part of the spectrum. These structures show a stable photoluminescence at room temperature which is sensitive to variations of the pH value and the applied bias voltage [1]. Biasing allows an adjustment of the working point to maximize the sensitivity. With each nanowire acting as an individual probe, dynamical imaging with biochemical contrast becomes feasible. The photoelectrode characteristics are dominated by radiative and non-radiative recombination of photo-generated electron-hole pairs that in turn are determined by the bias-dependent surface band bending in the nanowire electrodes. The photoelectrochemical properties of the InGaN/GaN nanowire are assessed by pH- and bias-dependent photocurrent and photoluminescence measurements.
[1] Wallys, J. et al., Nano Lett., 12, 6180-6186 (2012)