The fabrication and characterization of ZnO UV detector

ZnO films were deposited on GaAs substrates by radio frequency (rf) magnetron sputtering followed by an ambient-controlled heat treatment process for arsenic doping. In Hall measurements, the As-doped ZnO films showed the characteristics of p-type semiconductor. The ZnO thin film p-n homojuctions were then fabricated to investigate the electrical properties of the films. The p-n homojunctions exhibited the distinct rectifying current-voltage (I-V) characteristics. The turn-on voltage was measured to be ~3.0 V under the forward bias. When ultraviolet (UV) light (λ = 325 nm) was irradiated on the p-n homojunction, photocurrent of ~2 mA was detected. Based on these results, it is proposed that the p-n homojunction herein is a potential candidate for UV photodetector and optical devices.