Two-Dimensional Ruddlesden-Popper Perovskite with Nanorod-like Morphology for Solar Cells with Efficiency Exceeding 15%

Lai, HT (Lai, Hongtao)^[ 1,2 ] ; Kan, B (Kan, Bin)^[ 1,2 ] ; Liu, TT (Liu, Tingting)^[ 1,2 ] ; Zheng, N (Zheng, Nan)^[ 3 ] ; Xie, ZQ (Xie, Zengqi)^[ 3 ] ; Zhou, T (Zhou, Tong)^[ 1,2 ] ; Wan, XJ (Wan, Xiangjian)^[ 1,2 ] ; Zhang, XD (Zhang, Xiaodan)^[ 4 ] ; Liu, YS (Liu, Yongsheng)^[ 1,2 ] ; Chen, YS (Chen, Yongsheng)^[ 1,2 ]

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2018, 140(37): 11639-11646

DOI: 10.1021/jacs.8b04604

 WOS:000445439700019

Abstract

Two-dimensional (2D) Ruddlesden-Popper perovskites have shown great potential for application in perovskite solar cells due to their appealing environmental stability. However, 2D perovskites generally show poor photovoltaic performance. Here, a new type of 2D perovskite using 2-thiophenemethylammonium (ThMA(+)) as a spacer cation was developed and high photovoltaic performance as well as enhanced stability in comparison with its 3D counterpart was demonstrated. The use of the 2D perovskite (ThMA)(2)(MA)(n-1)PbnI3n+1,1 (n = 3) in deposited highly oriented thin films from N,N-dimethylformamide using a methylammonium chloride (MACI) assisted film-forming technique dramatically improves the efficiency of 2D perovskite photovoltaic devices from 1.74% to over 15%, which is the highest efficiency for 2D perovskite (n < 6) solar cells so far. the enhanced performance of the 2d perovskite devices using macl as additive is ascribed to the growth of a dense web of nanorod-like film with near-single-crystalline quality, in which the crystallographic planes of the 2d ma(n-1)pb(n)i(3n+1)(2-) slabs preferentially aligned perpendicular to the substrate, thus facilitating efficient charge transport. this work provides a new insight into exploration of the formation mechanism of 2d perovskites with increased crystallinity and crystal orientation suitable for high-performance solar cells.