Boost the efficiency of nickel oxide-based formamidinium-cesium perovskite solar cells to 21% by using coumarin 343 dye as defect passivator

Sanwan Liu, Rui Chen, Xueying Tian, Zhichun Yang, Jing Zhou, Fumeng Ren, Shasha Zhang, Yiqiang Zhang, Mengfan Guo, Yang Shen, Zonghao Liu, Wei Chen