Self-Powered and Broadband Bismuth Oxyselenide/p-Silicon Heterojunction Photodetectors with Low Dark Current and Fast Response

Inorganic nanomaterials such as graphene, black phosphorus, and transition metal dichalcogenides have attracted great interest in developing optoelectronic devices due to their efficient conversion between light and electric signals. However, the zero band gap nature, the unstable chemical properties, and the low electron mobility constrained their wide applications. Bismuth oxyselenide (Bi2O2Se) is gradually showing great research significance in the optoelectronic field. Here, we develop a bismuth oxyselenide/p-silicon (Bi2O2Se/p-Si) heterojunction and design a self-powered and broadband Bi2O2Se/p-Si heterojunction photodetector with an ultrafast response (2.6 μs) and low dark current (10-10 A without gate voltage regulation). It possesses a remarkable detectivity of 4.43 × 1012 cm Hz1/2 W-1 and a self-powered photoresponse characteristic at 365-1550 nm (ultraviolet-near-infrared). Meanwhile, the Bi2O2Se/p-Si heterojunction photodetector also shows high stability and repeatability. It is expected that the proposed Bi2O2Se/p-Si heterojunction photodetector will expand the applications of Bi2O2Se in practical integrated circuits in the field of material science, energy development, optical imaging, biomedicine, and other applications.