High-Performance Planar-Type Photodetector Based on Hot-Pressed CsPbBr3 Wafer.

Considering the disadvantages of the common methods for CsPbBr3 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 CsPbBr3 wafers. The effects of HP temperature on the phase purity of HP-CsPbBr3 wafers and the performance of the corresponding photodetectors have been investigated. The HP temperature for preparing phase-pure, shape-regular, and dense CsPbBr3 wafers has been optimized to be 150 °C, and the HP-CsPbBr3 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 × 1013 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.