Ultra-High 1.27 V V OC of Pure CsPbI3 Perovskite Solar Cells with an Efficiency of 21.8

• Published in: ACS energy letters Vol. 9; no. 10; pp. 4817 - 4826
• Main Authors: Yang, Shaomin, Wu, Meizi, Lei, Xuruo, Wang, Jungang, Han, Yu, He, Xuexia, Liu, Shengzhong, Liu, Zhike
• Format: Journal Article
• Language: English
• Published: American Chemical Society 11.10.2024
• DOI: 10.1021/acsenergylett.4c01323
• ISSN: 2380-8195

There are a large number of Pb-related defects in CsPbI3 perovskite due to the easy migration of halogen ions, which cause severe non-radiative recombination, leading to huge open circuit voltage (V OC) loss and power conversion efficiency (PCE) loss for CsPbI3 perovskite solar cells (PSCs). Herein, efficient and stable CsPbI3 PSCs are obtained by introducing a chlorosilane molecule (1,2-bis­(chlorodimethylsilyl)­ethane, CSE) into a perovskite precursor. CSE can effectively passivate the Pb-related defects, inhibit the non-radiative recombination, and adjust the energy level arrangement of PSCs to reduce the V OC loss. The champion CsPbI3 PSC achieves a high PCE of 21.8% and an amazing V OC of 1.27 V. In addition, the hydrolytic polymerization of CSE molecules builds a moisture barrier, which increases the stability of CsPbI3 PSCs. The unencapsulated CsPbI3 PSCs retain 90% of the initial PCE after storage in air for 1500 h; the encapsulated device retains 97% of the initial PCE after operation under continuous illumination for 440 h.