Antisolvent-fumigated grain growth of active layer for efficient perovskite solar cells

• A sealed antisolvent fumigation is proposed for fabricating high-quality perovskite layer. • Antisolvent-fumigated method facilitates the nucleation and crystal growth of perovskite thin-films. • Perovskite thin-films fumigated with antisolvent demonstrate excellent device performance. High efficiency of perovskite solar cell can be obtained through various approaches, including materials and interface engineering, device modification and fabrication techniques. In all approaches, the quality of the perovskite layer has a significant impact on the efficiency of the perovskite solar cell. Antisolvent dripping is widely used in almost all fabrication methodologies to achieve a high-quality perovskite layer. However, in the conventional antisolvent dripping, there are several factors (antisolvent volume, time and point of dripping, etc.) to be strictly followed. Due to these difficult and critical tricks, researchers often get perovskite layers with pinholes, small grains, and wide grain boundaries that deteriorate the performance of the perovskite solar cells. In order to produce perovskite films with large-scale grains, narrow boundaries and smooth surface morphology, a sealed antisolvent-fumigated process is implemented. There is no need to make any substantial efforts to achieve optimal conditions for the fabrication of high-quality perovskite layers using the antisolvent-fumigated strategy. Consequently, the efficiency of perovskite solar cell improves dramatically from 18.65% to 21.45%. Our findings present a new and convenient method for fabricating highly efficient perovskite solar cells.