Performance enhancement of perovskite solar cells via material quality improvement assisted by MAI/IPA solution post-treatment

The quality of the perovskite layer plays a key role in the performance of perovskite solar cells (PSCs). In this work, we demonstrate a facile way to improve the quality of perovskite films by using a MAI/IPA solution to post-treat the perovskite material after the film formation. XRD, SEM and AFM show that an optimal, uniform, dense and highly crystalline perovskite film is achieved after the post-treatment. The transient photocurrent and transient photovoltage also confirm that the devices after the post-treatment have both the outstanding ability of charge extraction and suppressed charge recombination. By using the post-treatment, a maximum PCE of 19.08%, which is 12% higher than that of the control device, is obtained with a J(sc) of 23.12 mA cm(-2), a V-oc of 1.08 V and an FF of 76.03%. The results show that the MAI/IPA solution post-treatment after the perovskite film formation is a facile way to improve the film quality and the PSC performance.