Initial Stages of Photodegradation of MAPbI_3 Perovskite: Accelerated Aging with Concentrated Sunlight

摘要

The initial stages of photo-degradation of CH_3NH_3PbI_3 (MAPbI_3) thin films priorto any significant change in light absorption are studied in experiments withindependent control of sample temperature and intensity of concentrated sunlightfrom 50 to 500 suns. Photo-stability of the MAPbI_3 film is revealed to beextremely sensitive to the sample temperature. Under the combined action oflight and heat (either by concentrated sunlight or by external heating), a strongreduction of the film photoluminescence (PL) without changes in the perovskitelight absorption can be observed during the initial stages of degradation. Incontrast, illumination of perovskite films (with intensity up to 500 suns) withoutheating (using chopped concentrated sunlight) induces considerable PLenhancement while the optical absorption spectrum remains unchanged. Withaccurate temperature control, aging under concentrated sunlight results insimilar instability trends as that under 1 sun.