Distinguish the Quenching and Degradation of CH3NH3PbI3 Perovskite by Simultaneous Absorption and Photoluminescence Measurements

Organometal halide perovskites have been one of the most promising alternative semiconductors in photovoltaic and light-emitting devices due to their excellent optoelectronic properties. However, the photophysical processes in these hybrid perovskites are still not fully understood. Photoluminescence (PL) of perovskite materials has been one of the most popular methods to investigate the photophysical processes in these materials. However, the PL signal only provides information of the radiative recombination of the charge carriers, which is not sufficient to understand the full picture of the photophysics. For example, both PL quenching and degradation of the materials cause decrease of PL intensity, which cannot be distinguished by PL. In this work, by simultaneously monitoring the absorption and PL of CH3NH3PbI3 perovskite during the photoexcitation with the assistance of microscopic technology, we followed the PL variation and the absorption change at the same time, allowing us to directly distinguish the PL quenching effect and structure change of the materials. These results provide us an effective way to investigate the perovskite materials from different aspects and further promote the understanding of their physical processes.