Enhancing Carrier Transport Properties of Melt-grown CsPbBr₃ Single Crystals by Eliminating Inclusions

All-inorganic perovskite CsPbBr₃ has attracted intense attentions due to its inspiring optoelectronic properties and excellent stability. Growing large-size single crystals with high quality is vital both for the intrinsic property investigation and the high-performance device fabrication. Here, large-size CsPbBr₃ single crystals (φ 30 mm × 100 mm) were grown by the modified Bridgman method. The surface morphologies of the as-grown CsPbBr₃ single-crystal wafers were characterized by SEM, and inclusions with size of 1-2 μm were observed in the first-time grown crystal (labeled as CPB-1). By adopting a slower growth rate (0.2 mm/h) and cooling rate (5 °C/h) than that of CPB-1, the inclusions were eliminated in subsequent growth (labeled as CPB-2). The hole mobility-lifetime products were measured to be 3.92 × 10^-3 and 1.46 × 10^-2 cm²·V^-1 for CPB-1 and CPB-2, respectively. The carrier mobility of CPB-2 was enhanced 1 order of magnitude from 10.1 ± 0.3 cm²·V^-1·s^-1 (CPB-1) to 101.3 ± 4.2 cm²·V^-1·s^-1 due to the elimination of inclusions. In addition, CPB-2 exhibited excellent α particles detection ability with the optimal energy resolution of 15.1% at -60 V bias. We provide an effective way to enhance the optoelectronic properties and device performance of melt-grown CsPbBr₃ single crystal by preventing the formation of the inclusions.