Aging-dependent trap deactivation behavior in MAPbI3 films under varied photon energy illumination

Organometal halide perovskites (OHPs) exhibit remarkable optoelectronic properties, such as wide visible absorption, high photoluminescence quantum yield, excellent solar-light-harvesting capabilities, and a low lasing threshold. Despite these advances, the best performance in perovskite typically occurs several hours to days post-fabrication, likely due to defect dynamics. The study of defect dynamics, particularly trap deactivation, is crucial for understanding and improving the stability and efficiency of OHPs. Furthermore, the effect of photon energy on these dynamics has not been fully explored. This study examined how aging impacts trap deactivation in MAPbI3 films under different photon energies using photoluminescence (PL). We found that aging significantly enhanced the deactivation of two types of traps, namely TL and TH, especially within the first 10 days. TL and TH ware traps in MAPbI3 that can be deactivated by low and high photon energy thresholds, respectively. PL enhanced more than doubled during this period, attributed to a small amount of oxygen penetration in vacuum conditions aiding trap deactivation. PL increased linearly with increasing aging, and trap deactivation time increased exponentially with age for both TL and TH deactivation. After 27 days, blue photon illumination resulted in reversible degradation and reactivation of the previously deactivated TL and TH traps. However, red photon illumination remained capable of deactivating the TL traps. This research highlights the interplay between light-induced trap dynamics and aging, which is crucial for optimizing MAPbI3 perovskite durability and performance in optoelectronic applications.