4-tert-butyl pyridine additive for moisture-resistant wide bandgap perovskite solar cells

Abstract

Perovskite solar cells fabrication process need inert or low humidity atmospheres. While highly efficient perovskite solar cells to overcome the photovoltaic marketing should be achieved stability at any environmental conditions. At high humidity, water molecules react with the perovskite layer and increase the degradation rate, leading to a drastic decrease in device performance and perovskite crystallinity. In this work, the effect of environmental humidity on photophysical parameters of wide bandgap, (WBG) perovskite layer and solar cells stability is systematically investigated and tBP is proposed as an additive in perovskite precursor to increase the moisture resistance and improve the crystallinity of the perovskite film, which is fabricated and kept at 80% RH. tBP act as a surface modification of the perovskite layer. According to SEM, XRD and water contact angle analysis, the crystallinity and hydrophobicity of the perovskite film improve by utilizing tBP. The stability and efficiency of the perovskite solar cells with tBP additive are higher than the perovskite solar cells without tBP. This work demonstrates that the engineering of the absorber precursor with a suitable additive could be a simple and low-cost strategy to reduce the effect of moisture in perovskite devices at high relative humidity.