Origin and Suppression of Nonradiative Recombination in Inorganic Halide Perovskites

The intrinsic defects of inorganic perovskites, characterized by shallow transition energy levels, confer a high degree of defect tolerance, which is crucial for enhancing the performance of optoelectronic devices. However, the effectiveness of these advanced devices is hindered by significant nonradiative recombination losses due to the presence of defects. Despite extensive efforts to mitigate nonradiative recombination, the underlying causes of these losses in perovskites remain unclear. In this study, we investigate the detrimental impact of hydrogen interstitials on CsPbBr3 and propose a pseudospring model for the nonradiative recombination mechanism involving hydrogen interstitials. Furthermore, by strategically manipulating the stretching mode of the pseudospring, we could effectively suppress nonradiative losses through targeted A-site and B-site engineering interventions. Finally, we reassess the micromechanistic basis of the remarkable defect tolerance observed in inorganic perovskites and elucidate the fundamental processes.