Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 62: Gallium Nitride: Optical and Electronic Properties

HL 62.10: Vortrag

Mittwoch, 9. März 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)