Study on the long time aging behavior of MAPbI: from experiment to first-principles simulation.

As the core functional layer of perovskite solar cells, the serious issues of the CHNHPbI film related to the long-term stability and its rapid degradation when exposed to the environment should be investigated deeply. In this study, the variation of phase construction, light absorption ability and fluorescence quenching ability during the long time aging process have been monitored. The results show that the degradation process is composed of the original serious fluorescence quenching and the lag behind phase decomposition.