Charge traps in lead-halide perovskites with different grain sizes

It is crucially required to understand charge traps in CH 3 NH 3 PbI 3 perovskites, which severely affect the charge recombination mechanism and hence have a critical impact on photovoltaic performance. Herein, we studied the photoexcited dynamics of CH 3 NH 3 PbI 3 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 CH 3 NH 3 PbI 3 perovskite solar cells on the basis of the recombination analysis.