Photoluminescence of GaN nanowires of different crystallographic orientations.

Chin, Alan H; Ahn, Tai S; Li, Hongwei; Vaddiraju, Sreeram; Bardeen, Christopher J; Ning, Cun-Zheng; Sunkara, Mahendra K · Nano Lett · 2007

basic_science · Level V

Where this comes from

Abstract

We utilized time-integrated and time-resolved photoluminescence of a-axis and c-axis gallium nitride nanowires to elucidate the origin of the blue-shifted ultraviolet photoluminescence in a-axis GaN nanowires relative to c-axis GaN nanowires. We attribute this blue-shifted ultraviolet photoluminescence to emission from surface trap states as opposed to previously proposed causes such as strain effects or built-in polarization. These results demonstrate the importance of accounting for surface effects when considering ultraviolet optoelectronic devices based on GaN nanowires.