Chemical Vapor Deposition Method Grown All-Inorganic Perovskite Microcrystals for Self-Powered Photodetectors.

Self-powered photodetectors (SPPDs) have attracted lots of attention due to their various advantages including no external power sources, high-sensitivity, fast response speed and so on. This study reports the fabrication and characterization results of CsPbBr3 microcrystals (MCs) grown by chemical vapor deposition (CVD) method, and the SPPDs have been fabricated on the basis of the CsPbBr3 MCs layer with the sandwich structure of GaN/CsPbBr3 MCs/ZnO. Such designed SPPD shows the detectivity (D*) of 1014 Jones, on/off ratio of up to 105, peak responsivity (R) of 89.5 mA/W and enhanced stability at the incident wavelength of 540 nm. The photodetector enables the fast photoresponse speed of 100 μs rise time and 140 μs decay time. The performances of the SPPD are comparable to the best ones ever reported for CsPbBr3 based PDs but no need external power supplies, which mainly benefits from the low trap density, long carrier diffusion of high quality CsPbBr3 MCs film and the built-in electric fields in the sandwich structure of GaN/CsPbBr3/ZnO layers.