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 (phi 30 mm x 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 mu m 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 degrees 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 x 10(-3) and 1.46 x 10(-2) cm(2).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 cm(2).V-1.s(-1) (CPB-1) to 101.3 +/- 4.2 cm(2).V(-1)s(-1) due to the elimination of inclusions. In addition, CPB-2 exhibited excellent a 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.