Self-powered, high-speed Sb2Se3/Si heterojunction photodetector with close spaced sublimation processed Sb2Se3 layer

Abstract

Antimony selenide (Sb2Se3) has received great attention recently due to its excellent carrier transport capacity and special one-dimensional crystal structure. The Sb2Se3-based bulk heterojunctions have been applied for photovoltaic with great success, but its potential application to photodetector has not been explored yet. In this work, a self-powered, high-speed Sb2Se3/Si heterojunction photodetector is fabricated and investigated, where the Sb2Se3 layer is deposited through close spaced sublimation (CSS) technique. The photodetector exhibits detection performance with a responsivity of 0.34 A/W at zero bias voltage and a broad spectral range from 300 to 1100 nm. Ultrafast response rise and fall times of 86 and 96 μs, respectively, are obtained, which is significantly better than previous reports of Sb2Se3-based photodetectors. The high crystallographic quality of the CSS-processed Sb2Se3 thin films and the built-in field at the Sb2Se3/Si interface is responsible to the high response speed of Sb2Se3/Si heterostructural photodetectors. The high-speed and broadband response properties make the Sb2Se3/Si heterojunction photodetector have potential applications for next-generation optoelectric devices.