Pressure controlled anti-solvent spreading for improved current signal with effective grain growth in perovskite optoelectronic devices

Abstract

In this study, a strategy is proposed to control the injection pressure during solvent processing for the fabrication of high-quality perovskite thin films, aiming to enhance the performance of intrinsically perovskite-based optoelectronic devices. Low-pressure solvent injection with a large injection area promotes larger crystal grain size and minimizes film damage, leading to a significant increase in shunt resistance and a reduction in defect density. This effectively suppresses the dark current in perovskite photodetectors (PPDs). Furthermore, in a stability test conducted under ambient air conditions (>60% humidity) for 72 h, devices treated with broad spreading retained 81% of their initial power conversion efficiency (PCE), exhibiting approximately 17% higher efficiency retention compared to those treated with narrow spreading. These results clearly demonstrate that the low-pressure anti-solvent injection strategy substantially improves device stability. Therefore, by simply controlling the anti-solvent injection area, both the crystal quality and long-term stability of perovskite-based optoelectronic devices can be simultaneously optimized.