Multiple-Noncovalent-Interaction-Stabilized Layered Dion-Jacobson Perovskite for Efficient Solar Cells

Lv, GW (Lv, Guangwei) 1, 2Li, L (Li, Ling) 3, 4Lu, D (Lu, Di) 1, 2Xu, ZY (Xu, Zhiyuan) 1, 2Dong, YX (Dong, Yixin) 1, 2Li, QH (Li, Qiaohui) 1, 2Chang, ZT (Chang, Zhitao) 1, 2Yin, WJ (Yin, Wan-Jian) 3, 4Liu, YS (Liu, Yongsheng) 1, 2

NANO LETTERS, 2021, 21(13): 5788-5797

DOI 10.1021/acs.nanolett.1c01505

Abstract

Two-dimensional Dion-Jacobson (DJ) perovskites have shown improved structure stability in comparison with Ruddlesden-Popper (RP) perovskites. However, the mechanism behind the improved stability is still largely unexplored. Here a multifluorinated aromatic spacer, namely, 4F-PhDMA, has been successfully developed for 2D DJ perovskites. It is found that the 2D DJ perovskite with a 4F-PhDMA spacer exhibits a high dissociation energy due to the multiple noncovalent interactions. The optimized 2D DJ device based on the 4F-PhDMA spacer (n = 4) exhibits a champion efficiency of 16.62% with much improved light and thermal stability. This efficiency is much higher than that of the control device using an unfluorinated spacer (n = 4, PCE = 10.11%) and is among the highest efficiencies in aromatic-spacer-based 2D DJ perovskite solar cells (PSCs). Our work highlights the importance of incorporating multiple noncovalent interactions in the 2D DJ perovskite by employing a multifluorinated aromatic spacer to achieve DJ PSCs with both high efficiency and high stability.