AlGaN/GaN MSM photodetectors with photo-CVD annealed Ni/Au semi-transparent contacts

AlGaN/GaN metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors with photo-chemical vapour deposition (photo-CVD) annealed Ni/Au semi-transparent contacts were fabricated. It was found that the transmittances of Ni/Au films increased while the photodetector dark currents became significantly lower after annealing. With a 5 V applied bias, it was found that the photocurrent to dark current contrast ratio and the maximum responsivity were 2.3 x 10(4) and 0.166 A W-1 for photodetector photo-CVD annealed at 550 degreesC.