Ultrasensitive and High-Speed Ga2O3 Solar-Blind Photodetection Based on Defect Engineering

Oxygen vacancy (VO) defects are ubiquitous in oxide semiconductors and usually served as charge carriers recombination centers to depress the device performance. Herein, a surface VO defect compensation engineering is conducted to modulate the VO and improve the device performance of [Formula Omitted]-Ga2O3 film via oxygen-plasma treatment. As a result, the photodetectors (PD) based on 30 min oxygen-plasma treated Gallium oxide (Ga2O3) film not only exhibit record-low dark current of 5 fA, over three orders of magnitude times higher responsivity rejection ratio ([Formula Omitted], and faster rise and decay speed than the untreated device but also the oxygen-plasma-treated PDs exhibits exceptional sensitivity to detect extremely weak UV signals ([Formula Omitted]/cm[Formula Omitted] with a photo-to-dark current ratio of [Formula Omitted]. Also, it is discovered that the device based on oxygen plasma has excellent photoelectric stabilities. The defect engineering with surface plasma treatment offers an efficient strategy for the high performance of Ga2O3 film devices.