Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 44: Quantum Dots: Optical Properties II

HL 44.4: Talk

Tuesday, March 21, 2017, 15:30–15:45, POT 81

Light-trapping and Waveguide Characteristics of Selective Area Grown GaN Nanowires on Transparent Substrates — •Richard Hudeczek, Julia Winnerl, and Martin Stutzmann — Walter Schottky Institut, Garching bei München, Germany

During the last decade group-III-nitride nanowires (NWs) have attracted increasing interest for device fabrication due to their high crystalline quality, e.g. for optoelectronic devices. Their large surface-to-volume ratio is advantageous for sensing or catalysis applications. Another interesting aspect is that NWs constitute intrinsic waveguides because of their one-dimensional geometry. The control of the NW density and diameter is essential for the reproducible fabrication of NW-based devices. The position-controlled growth of GaN NWs by molecular beam epitaxy can be achieved by using a patterned Ti mask as already reported by several groups [1,2].

Here, we present optical measurements of selective area grown GaN NWs on transparent substrates, e.g. c-plane sapphire and GaN based light emitting diode substrates. This allows backside illumination of as-grown NW arrays through the growth substrate. In particular, the dependence of the light trapping on the NW diameter (ranging from 70 to 220 nm), NW period which is varied between 300 and 2000 nm and the illumination wavelength (in the range of 400 to 620 nm) is investigated. Moreover, the experimental findings are compared to numerical simulations.

[1] K. Kishino, et al., J. Crystal Growth 311, 2063 (2009)

[2] F. Schuster, et al., Nano Lett. 15, 1773 (2015)