Charge traps in lead-halide perovskites with different grain sizes

It is crucially required to understand charge traps in CH3NH3PbI3 perovskites, which severely affect the charge recombination mechanism and hence have a critical impact on photovoltaic performance. Herein, we studied the photoexcited dynamics of CH3NH3PbI3 perovskites with different grain sizes by measuring the intensity dependence of time-resolved photoluminescence (PL). As a result, we found that the PL decay for all the samples can be well analyzed using bimolecular radiative recombination and trap-assisted Shockely-Read-Hall recombination models. We discuss how the PL dynamics impact the photovoltaic performance of CH3NH3PbI3 perovskite solar cells on the basis of the recombination analysis. (C) 2018 The Japan Society of Applied Physics