Ultraviolet Detection Based on AlGaN/GaN Heterojunction Under Low-Temperature

We fabricated and tested an ultraviolet metal-semiconductor-metal photodetector based on dual-color AlGaN/GaN heterostructure. The photodetector’s optical responsivity and current-voltage characteristics were investigated. The annealing process significantly improved their optical responsivity and reduced their dark current by two orders of magnitude. The peak responses were 4.255 A/W at 288 nm and 2.929 A/W at 366 nm under a bias of 5 V. We also studied the bias voltage-dependent photoelectricity behaviors of the photodetector at a temperature of 77 K. The rise time and fall time of the photodetector both decrease with the increase of the bias voltage at 77 K.