Stable Perovskite Solar Cells with Improved Hydrophobicity Based on BHT Additive
Abstract
Remarkable progress has been achieved in organometallic halide perovskite solar cells (PSCs). However, poor environmental stability of PSCs has been proved to be challenging and needs further improvement. Here, a strategy of butylated hydroxytoluene (BHT) antioxidant additive with hydrophobic tert butyl and hydrophilic hydroxyl is developed to enhance the hydrophobicity, control nucleation rate and passivate the defect states of perovskite. The tert butyl group effectively prevents the penetration of moisture, as well as the formed hydrogen bond between hydroxyl group and iodine controls the assembly process of BHT and perovskite. By optimizing weight ratio of BHT and MAPbI3 in precursor solution, the power conversion efficiency of PSCs increased from 14.93% to 18.28% and greatly enhanced device stability compared with control device. We believe that our tactic of BHT additive can be applied to various perovskite films and will facilitate the realization of stable perovskite optoelectronics.
