Title :
Efficient GaN photocathodes for low-level ultraviolet signal detection
Author :
Shahedipour, Fatemeh S. ; Ulmer, Melville P. ; Wessels, Bruce W. ; Joseph, Charles L. ; Nihashi, Tokuaki
Author_Institution :
CESTM, State Univ. of New York, Albany, NY, USA
fDate :
4/1/2002 12:00:00 AM
Abstract :
We report on the properties of GaN-based photocathodes for low light ultraviolet (UV) signal detection. Cesiated Mg-doped p-type GaN layers with 1-μm thickness were used as photocathode materials. Quantum efficiency (QE) as measured on a completed device showed values as high as 30% at 200 nm. A UV/visible rejection ratio of three orders of magnitude at 500 nm was observed. A net increase in the QE was also observed with increasing conductivity of the material
Keywords :
III-V semiconductors; caesium; dark conductivity; electron affinity; gallium compounds; magnesium; photocathodes; photodetectors; ultraviolet detectors; wide band gap semiconductors; 1 micron; 200 nm; 500 nm; GaN:Mg; GaN:Mg-Cs; UV/visible rejection ratio; cesiated Mg-doped p-type GaN layers; conductivity; efficient GaN photocathodes; low-level ultraviolet signal detection; phototube; quantum efficiency; solar-blind detector; Astronomy; Cathodes; Conducting materials; Dark current; Detectors; Electrons; Gallium nitride; Photodetectors; Signal detection; Surface treatment;
Journal_Title :
Quantum Electronics, IEEE Journal of
