High-Performance Planar-Type Photodetector Based on Hot-Pressed CsPbBr 3 Wafer.

Considering the disadvantages of the common methods for CsPbBr 3 single crystal growth including the high cost of the melt method and the low shape controllability of the solution method, a facile hot-pressed (HP) approach has been introduced to prepare CsPbBr 3 wafers. The effects of HP temperature on the phase purity of HP-CsPbBr 3 wafers and the performance of the corresponding photodetectors have been investigated. The HP temperature for preparing phase-pure, shape-regular, and dense CsPbBr 3 wafers has been optimized to be 150 °C, and the HP-CsPbBr 3 wafer based planar-type photodetectors exhibit an ultrasensitive weak light photoresponse. Under the illumination of a 530 nm LED with a light power density of 1.1 μW cm -2 , the responsivity, external quantum efficiency, and detectivity of the devices reach 19.79 A W -1 , 4634%, and 2.14 × 10 13 Jones, respectively, and a fast response speed with a rise time of 40.5 μs and a fall time of 10.0 μs has been achieved.