Multifunctional succinate additive for flexible perovskite solar cells with more than 23% power-conversion efficiency

Flexible perovskite solar cells (FPSCs) have emerged as power sources in ver-satile applications owing to their high-efficiency characteristics, excellent flex-ibility, and relatively low cost. Nevertheless, undesired strain in perovskite films greatly impacts the power-conversion efficiency (PCE) and stability of PSCs, particularly in FPSCs. Herein, a novel multifunctional organic salt, methylam-monium succinate, which can alleviate strain and reinforce grain boundaries, was incorporated into the perovskite film, leading to relaxed microstrain and a lower defect concentration. As a result, a PCE of 25.4% for rigid PSCs and a record PCE of 23.6% (certified 22.5%) for FPSCs have been achieved. In addi-tion, the corresponding FPSCs exhibited excellent bending durability, maintain-ing-85% of their initial efficiency after bending at a 6 mm radius for 10 000 cycles.

Automated summary

This study introduces a new method to improve the strain issue and enhance the efficiency and stability of flexible perovskite solar cells by incorporating a novel organic salt. The approach achieves high power-conversion efficiency and demonstrates excellent bending durability.