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 × 10 4 and 0.166 A W −1 for photodetector photo-CVD annealed at 550 °C.