Photoluminescence of GaN nanowires of different crystallographic orientations.
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.
Chin
Alan H
AH
Center for Advanced Aerospace Materials and Devices, NASA Ames Research Center, Moffett Field, California 94035, USA. achin@mail.arc.nasa.gov
Ahn
Tai S
TS
Li
Hongwei
H
Vaddiraju
Sreeram
S
Bardeen
Christopher J
CJ
Ning
Cun-Zheng
CZ
Sunkara
Mahendra K
MK