Deep-ultraviolet solar-blind photoconductivity of individual gallium oxide nanobelts

Abstract

We designed solar-blind deep-ultraviolet semiconductor photodetectors using individual Ga₂O₃ nanobelts. The photoconductive behavior was systematically studied. The photodetectors demonstrate high selectivity towards 250 nm light, fast response times of less than 0.3 s, and a large photocurrent to dark current ratio of up to 4 orders of magnitude. The photoresponse parameters such as photocurrent, response time, and quantum efficiency depend strongly on the intensity of light, the detector environment, and the nanobelt size. The photoresponse mechanism was discussed, which was mainly attributed to the band bending, surface traps, and distribution of traps in the bandgap. Present Ga₂O₃ nanobelts can be exploited for future applications in photo sensing, light-emitting diodes, and optical switches.