Photoelectrochemical Self-Powered Solar-Blind Photodetectors Based on Ga₂O₃ Nanorod Array/Electrolyte Solid/Liquid Heterojunctions with a Large Separation Interface of Photogenerated Carriers

Solar-blind photodetectors have been widely developed because of their great potential application in biological analysis, ultraviolet communication, and so on. Photodetectors constructed by vertically aligned nanorod arrays (NRAs), have attracted intensive interest recently owing to the virtues of low light reflectivity and rapid electron transport. However, limited by the insufficient contact between the upper electrode and NRAs because of uneven NRAs, photogenerated carriers cannot be effectively separated and transferred. In this work, a novel photoelectrochemical (PEC) type self-powered solar-blind photodetectors constructed in the form of Ga2O3 NRAs/electrolyte solid/liquid heterojunction with a large photogenerated carrier separation interface has been fabricated, β-Ga2O3 NRAs PEC photodetector shows a photoresponsivity of 3.81 mA/W at a bias voltage of 0 V under the 254 nm light illumination with the light intensity of 2.8 mW/cm2, thus yielding a Iphoto/Idark ratio of 28.97 and an external quantum efficiency of 1.86%. Our results provide a novel device structure of solar-blind photodetector with high efficient deep-ultraviolet photodetection and low power consumption.