High-performance CH3NH3PbBr3 Polycrystalline Wafer Prepared by Hot-pressing Method

Abstract

Considering the drawbacks of the common methods for CH3NH3PbBr3 single crystal growth, such as the complicated and uncontrollable process, a simple hot-pressing (HP) method was introduced to fabricate CH3NH3PbBr3 polycrystalline wafers. The effect of hot-pressing temperature on the crystalline quality and corresponding optical and electrical properties of the CH3NH3PbBr3 polycrystalline wafers was investigated. The hot-pressing temperature for CH3NH3PbBr3 was optimized at 150°C, and the optimized CH3NH3PbBr3 wafer exhibited a low defect density (1.55×1010 cm−3), long carrier lifetime (1734 ns), and high carrier mobility (51.24 cm2V−1s−1) as a photoconductive detector. Furthermore, the detector showed a highly sensitive weak light response under 525 nm LED illumination with an optical power density of 84 nWcm−2, exhibiting a high responsivity of 63 AW−1, EQE of 1.5×104 %, and detectivity of 2.33×1013 Jones, and a fast response speed with a rise time of 17.7 μs and a fall time of 57.4 μs has been achieved.