RESUMEN
Herein, we demonstrate that triacetyl resveratrol (TRES) can be employed as an antioxidant additive to suppress the formation of oxidation-induced defects in air-fabricated perovskite films. When assembling into carbon-based CsPbIBr2 and CsPbI2Br cells, an enhanced efficiency of 10.38% and 14.98% has been achieved, with nearly unchanged efficiency after 1128 h of shelf storage in air and 86% of the initial efficiency after >1000 h aging at 85 °C.
RESUMEN
Perovskite solar cells (PSCs) have attracted extensive attention in photovoltaic applications owing to their superior efficiency, and the buried interface plays a significant role in determining the efficiency and stability of PSCs. Herein, a plant-derived small molecule, ergothioneine (ET), is adopted to heal the defective buried interface of CsPbIBr2-based PSC to improve power conversion efficiency (PCE). Because of the strong interaction between Lewis base groups (-CâO and -CâS) in ET and uncoordinated Pb2+ in the perovskite film from the theoretical simulations and experimental results, the defect density of the CsPbIBr2 perovskite film is significantly reduced, and therefore, the nonradiative recombination in the corresponding device is simultaneously suppressed. Consequently, the target device achieves a high PCE of 11.13% with an open-circuit voltage (VOC) of 1.325 V for hole-free, carbon-based CsPbIBr2 PSCs and 14.56% with a VOC of 1.308 V for CsPbI2Br PSCs. Furthermore, because of the increased ion migration energy, the detrimental phase segregation in this mixed-halide perovskite is weakened, delivering excellent long-term stability for the unencapsulated device in ambient conditions over 70 days with a 96% retention rate of initial efficiency.