A facileway to improve the performance of perovskite solar cells by toluene and diethyl ether mixed anti-solvent engineering

Abstract

Solvent engineering is one of the most widely applied preparation methods for the highquality perovskite films. In this method, the choice of anti-solvent plays a very important role to improve the perovskite crystal quality. Here, we report a facile way to regulate the crystal quality of perovskite film by adjusting the ratio of toluene and diethyl ether in the mixed anti-solvent. Through the combination of characterization and measurements including scanning electron microscopy, the atomic force microscopy, X-ray diffraction, and the steady-state photoluminescence spectra, it reveals that the quality of perovskite films is obviously improved when the volume ratio of toluene to diethyl ether in the mixed anti-solvent is 1:1. The optimal device obtains power conversion efficiency of 16.96% with a short-circuit current density of 20.60 mA/cm2, an open-circuit voltage of 1.03 V, and a fill factor of 79.96%. At the same time, the device shows negligible current-voltage hysteresis and steady power output. Moreover, the stability of PSCs is significantly enhanced due to the perovskite film quality improvement by adopting 50% toluene mixed anti-solvent.