Influence of anti-solvents on CH3NH3PbI3 films surface morphology for fabricating efficient and stable inverted planar perovskite solar cells

Abstract

The stability of perovskite solar cells (PSCs) are critically related to the perovskite crystal morphology and film quality, hence controlling the perovskite film formation is one of the key concerns. In this study, we have used four anti-solvents-toluene, chlorobenzene, p-xylene and ether to fabricate high quality CH3NH3PbI3 perovskite films. We investigated the surface morphology, optical and structural properties of the corresponding perovskite films. Consequently, PSCs with variation of these anti-solvents were fabricated and the respective photovoltaic performances over a period of 30 days in dark and under air mass 1.5G sunlight conditions have been observed. Our analyses onto the post fabrication of PSCs highlight that, the perovskite films formed by toluene, chlorobenzene and p-xylene treatment results in high efficient and stable PSCs in dark. Interestingly, the ether treated PSC had no photovoltaic response after 10 days. The toluene and chlorobenzene treated PSCs showed stable device performance and retained. 90% of their initial power conversion efficiency even after 30 days light soaking. The p-xylene treated PSCs showed unstable performance during the same light soaking period.