Self-Powered Dual-Color UV-Green Photodetectors Based on SnO Millimeter Wire and Microwires/CsPbBr Particle Heterojunctions.

Multiband detection has always been a challenge and has drawn much attention in the development of photodetectors (PDs). Herein, we present controllable synthesis of SnO wires with different sizes via chemical vapor deposition and formed composites with CsPbBr particles to realize dual spectral response. We constructed PDs based on a single SnO millimeter wire decorated with CsPbBr particles (SnO MMW/CsPbBr), which showed a stepped spectrum, fast response speed, and self-powered function. Meanwhile, SnO microwires/CsPbBr composites (SnO MWs/CsPbBr) were also utilized to fabricate PDs. It is noteworthy that detection occurred in two different wavelength bands (320 and 520 nm) with equivalent intensity at a bias of 0 V. The self-powered feature of this device comes from the built-in electric field at the interface of SnO/CsPbBr, and the dual-color response originates from asymmetric junction barriers between conduction bands of SnO and CsPbBr. This work demonstrated promising self-powered PDs that are capable of multiband detection.