Fabrication of beta-Ga2O3/ZnO heterojunction for solar-blind deep ultraviolet photodetection

摘要

A thin-film type beta-Ga2O3/ZnO heterojunction was constructed for the first time by radio frequency magnetron sputtering of a beta-Ga2O3 layer on a (0001) ZnO single crystalline substrate. The heterojunction presents a typical positive rectification in the dark, and shows a solar-blind deep ultraviolet photoelectric characteristic. Under zero bias, the photodetector based on a beta-Ga2O3/ZnO heterojunction exhibits an I-photo/I-dark ratio of similar to 14.8 under a 254 nm light illumination with a light intensity of 50 mu Wcm(-2), showing a characteristic of working with zero power consumption. The photocurrent linear increases and the response time decreases with the increase of the light intensity. The photodetector shows a R-lambda of 0.35 AW(-1) and an EQE of 1.7. x. 10(2)% under 254 nm illumination of 50 mu Wcm(-2) and a negative bias of 5 V. This study presents a promising candidate for use in solar-blind deep ultraviolet photodetection.