Electrically controlled interface state distribution for improving pyro-phototronic photosensing from UV to NIR

Abstract

The interface states (ISs) in oxide semiconductor have long been considered a key factor for limiting the photoresponse performance of oxide-based photodetectors (PDs). Here, the IS distribution is electrically tailored and proposed as an effective strategy to improve the performances of the ZnO-based PDs. A graded IS (GIS) with tunable gradient is achieved through an electric field-assisted UV irradiation to significantly enhance the built-in electric field of the heterojunction. The corresponding steady (transient) photocurrent responsivity of the heterojunction as a self-powered PD is thus improved by a maximal factor of 1540% (237%) relative to the junction under the initial IS condition for 320-1120 nm waves. More importantly, the tunable IS distribution can modulate pyro-phototronic effect. This work provides an effective approach to manipulate IS distribution in oxide semiconductor and a potential perspective on using disorder IS to design the self-powered PDs.