Optimal Methylammounium Chloride Additive for High-Performance Perovskite Solar Cells

Organic-inorganic lead halide perovskite solar cells (PSCs) have presented promising improvements within recent years due to the superior photophysical properties of perovskites. The efficiency of PSCs is closely related to the quality of the of the perovskite film. Additive engineering is an effective strategy to regulate the crystallization of perovskite film. Therefore, in this work, we introduce methylammounium chloride (MACl) into a perovskite precursor as an additive to improve the crystallization of perovskite film and to suppress the formation of defects to achieve high-performance PSCs. By meticulously investigating and studying the influence of different percentages of MACl additives on perovskite film quality, we obtain that the best amount of incorporated MACl is 10%. Thanks the employment of the optimal amount of MACl, the perovskite film shows a significantly improved morphology with larger grains, a smoother surface, and suppressed defects. Finally, the target PSCs with the addition of 10% MACl present the highest PCE of 23.61%, which is much higher than the value (16.72%) of the control device.