Determination of Defect Levels in Melt-Grown All-Inorganic Perovskite CsPbBr3 Crystals by Thermally Stimulated Current Spectra

Abstract

Further improvement of optoelectronic performance is a target for all-inorganic lead halide perovskite material CsPbBr3; however, it is greatly limited by the quality of the material which is dominated to some extent by defects, especially intrinsic point defects. In this study, the intrinsic point defects in melt-grown CsPbBr3 crystals were studied by thermally stimulated current technology and the simultaneous multiple peak analysis (SIMPA) method. The defect formation mechanism was analyzed systematically by combining the SIMPA fitting results with defect-related parameters, material properties, and external conditions. The main analytical defects, VCs and VBr vacancies, Csi and Pbi interstitials, and PbBr antisites, matched up with theoretical prediction well. Such systematic studies of defect types and concentration give us more insights into the carrier transport mechanism of CsPbBr3 and will help us find ways to improve the crystal quality by controlling the types and concentration of point defects.