Ambience dependent photoluminescence reveals the localization and trap filling effects in CH3NH3PbI3−xClx perovskite films.

The photophysics of organolead trihalide perovskites are still not fully understood. Here we report that the photoluminescence (PL) lineshape, decay features, and intensity of solution-processed CH₃NH₃PbI_3−xCl_x films are highly sensitive to the ambience. The radiative recombination actually consists of two decay channels corresponding to recombination of extended and localized states, respectively. The PL decay can be well described by a model considering the carrier localization, surface band bending, and trapping–detrapping of carriers. [ABSTRACT FROM AUTHOR]