Perovskite Solar Cells Prepared with Multifunctional Alcohol Additives for Enhanced Thermal Stability and Optoelectronic Performance

In recent years, CsFAMAPbI1-xBrx-based lead halide perovskite solar cells have been widely studied for their high efficiency. However, lead-based perovskite films exhibit inherent defects, leading to significant stability degradation under high humidity and temperature. In this study, we used three alcohol additives (IPA, IBA, and NBA) combined with CB-PMMA to form mixed solutions, focusing on their effects on large grain formation and thermal stability enhancement. The CB-PMMA mixed solution provided the least improvement in thermal stability, with CsFAMAPbI1-xBrx films degrading after annealing at 150 °C for 9 hours. In contrast, the CB/IPA-PMMA, CB/IBA-PMMA, and CB/NBA-PMMA mixed solutions significantly enlarged perovskite grain sizes, reduced grain boundary counts, lowered carrier recombination at grain boundaries, and improved device photocurrent and fill factor. The optimized perovskite films maintained a high photoelectric conversion efficiency of 15.42% after annealing at 150 °C for 9 hours, demonstrating excellent thermal stability.