Perovskite solar cells with PCE over 19% fabricated under air environment by using a dye molecule additive

Abstract

A typical solution-processed perovskite film possesses numerous defects, especially when fabricated under high-humidity ambient conditions, which severely limits the performance of planar perovskite solar cells (PSCs). Here, the unique fluorescent dye molecule additive of 3-(2-benzimidazolyl)-7-(diethylamino)-coumarin (8GFF) is introduced into a perovskite film to address the defect issues. With the addition of 8GFF, its functional groups (–COO) can interact with Pb²⁺ ions, thereby minimizing the ionic defects in the perovskite film and improving its crystalline quality. And the optimized charge transport with decreased recombination loss can also be realized. Besides, the introduction of 8GFF increases the absorption capacity of the device in a green light wave band, beneficial for photocurrent enhancement. Consequently, the device fabricated in an air environment without a glove box exhibits a promising efficiency of 19.16%, superior to 15.61% of the control device. This work demonstrates the potential applications for fabricating high-performance planar devices regarding the aspects of fluorescent dyes.