Simply equipped ε-Ga2O3 film/ZnO nanoparticle heterojunction for self-powered deep UV sensor

Abstract

Abstract In this paper, a ε-Ga2O3 film/ZnO nanoparticle hybrid heterojunction deep ultraviolet (UV) photodetector is described for 254 nm wavelength sensing application. The constructed ε-Ga2O3/ZnO heterojunction photodetector can operate in dual modes which are power supply mode and self-powered mode. Under reverse 5 V bias with 254 nm light intensity of 500 μW cm−2, the photoresponsivity, specific detectivity and external quantum efficiency are 59.7 mA W−1, 7.83 × 1012 Jones and 29.2%. At zero bias, the advanced ε-Ga2O3/ZnO photodetector performs decent self-powered photoelectrical properties with photo-to-dark current ratio of 1.28 × 105, on/off switching ratio of 3.22 × 104, rise/decay times of 523.1/31.7 ms, responsivity of 4.12 mA W−1 and detectivity of 2.24 × 1012 Jones. The prominent photodetection performance lays a solid foundation for ε-Ga2O3/ZnO heterojunction in deep UV sensor application.