Highly efficient all-inorganic perovskite solar cells with suppressed non-radiative recombination by a Lewis base

• Published in: Nature communications Vol. 11; no. 1; p. 177
• Main Authors: Wang, Jing, Zhang, Jie, Zhou, Yingzhi, Liu, Hongbin, Xue, Qifan, Li, Xiaosong, Chueh, Chu-Chen, Yip, Hin-Lap, Zhu, Zonglong, Jen, Alex K Y
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 10.01.2020; Nature Publishing Group UK; Nature Portfolio
• Subjects: Efficiency; Interlayers; Lewis base; Open circuit voltage; Perovskites; Photovoltaic cells; Radiative recombination; Recombination; Solar cells; Thermal stability
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-13909-5

All-inorganic perovskite solar cells (PVSCs) have drawn increasing attention because of their outstanding thermal stability. However, their performance is still inferior than the typical organic-inorganic counterparts, especially for the devices with p-i-n configuration. Herein, we successfully employ a Lewis base small molecule to passivate the inorganic perovskite film, and its derived PVSCs achieved a champion efficiency of 16.1% and a certificated efficiency of 15.6% with improved photostability, representing the most efficient inverted all-inorganic PVSCs to date. Our studies reveal that the nitrile (C-N) groups on the small molecule effectively reduce the trap density of the perovskite film and thus significantly suppresses the non-radiative recombination in the derived PVSC by passivating the Pb-exposed surface, resulting in an improved open-circuit voltage from 1.10 V to 1.16 V after passivation. This work provides an insight in the design of functional interlayers for improving efficiencies and stability of all-inorganic PVSCs.