Effects of water additive and moisture on the performance of Dion-Jacobson perovskite [C6H4(CH2NH3)2](CH2NH3)3Pb4I13 solar cells

This work applies comprehensively researches on the influence of water as an additive in precursor solution, and the moisture (65 % relative humidity) on the performance of Dion-Jacobson (DJ) perovskite [C6H4(CH2NH3)2] (CH2NH3)3Pb4I13 solar cells. The results indicate that 3 %−15 % (v/v) water as an additive has minor effect on the power conversion efficiency (PCE) of fresh prepared solar cells, but it can improve the resistance of device to humidity. More importantly, with an appropriate ratio of water additive and moister action time, the perovskite film shows a smoother surface, higher coverage, and better crystallinity, resulting in an optimal PCE of ∼ 8 %, compared to ∼ 1 % of fresh prepared one. Our results are helpful to understand the effect of water and moisture on DJ perovskite solar cells, may contributing to develop rational strategies to improve devices' stability under humidity ambient.