Charge traps in lead-halide perovskites with different grain sizes

Abstract

It is crucially required to understand charge traps in CH3NH3PbI3 perovskites, which severely affect 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 intensity dependence of time-resolved photoluminescence. As a result, we found that the photoluminescence (PL) decay for all the samples can be well analyzed by bimolecular radiative recombination and trap-assisted Shockely-Read-Hall recombination model. We discuss how the PL dynamics impact on the photovoltaic performance of CH3NH3PbI3 perovskite solar cells on the basis of the recombination analysis.

Effect of formamidinium (FA) ions on mixed ‘A’-site based bromide perovskite (APbBr3) thin films

“…As a result, the charge carriers in the FA 0.5 MA 0.4 Cs 0.1 PbBr 3 perovskite flow without many barriers. 36 On the other hand, in the MA 0.9 Cs 0.1 PbBr 3 perovskite, the flow of charge carriers is more restricted and the possibility of accumulation of charge carriers in the perovskite material is more, resulting in a higher R ct .…”

A Direct Mapping Approach to Understand Carrier Relaxation Dynamics in Varied Regions of a Polycrystalline Perovskite Film

“…The limiting factors for rapid charge separation and slow charge recombination are determined by how many trap states, defects and dislocations of the carriers throughout the perovskite film in bulk crystals or in the boundaries of the crystals . There have been reported that the bigger size of the crystals gives the better overall device performance due to a better crystal growth control to increase the charge transport rate and to decrease the electron‐hole recombination rate . In contrast, Don et al .…”