2D multilayered perovskites based on 4-chlorophenylethylamine for solar cell application

Two-dimensional layered organic-inorganic perovskite hybrids have attracted increasing attention due to their outstanding moisture resistance and promising optoelectronic properties. However, the photovoltaic performance in solar cells is still a huge challenge for two-dimensional perovskite films. With the aim to improve the efficiency of 2D perovskite solar cells, the new (ClC 6 H 4 C 2 H 4 NH 3 ) 2 MA n−1 Pb n I 3n+1 perovskite family (abbreviated as (CPEA) 2 MA n−1 Pb n I 3n+1 ) are synthesized by a simple one-step hot-casting method in this study. It is found that the variation of n value (n = 3–6) has great influence on the microstructure, grain size, charge mobility, trap density and photovoltaic performance of the 2D (CPEA) 2 (MA) n−1 Pb n I 3n+1 . Due to the best film quality and prolonged carrier lifetime, the (CPEA) 2 MA 4 Pb 5 I 16 (n = 5) perovskite solar cell exhibits a highest efficiency of 11.86%, with a V oc of 0.989 V, a J sc of 19.92 mA/cm 2 and FF of 60%, respectively. It is anticipated that our approach to explore new organic spacer cations in 2D perovskites may pave the way for their application with high performance.