Synergetic Effect on Enhanced Photovoltaic Performance of Spray-Coated Perovskite Solar Cells Enabled by Additive Doping and Antisolvent Additive Spraying Treatment

Improving perovskite film quality is essential for making solar cells with enhanced performance. A critical bottleneck for progress in perovskite solar cell science is the lack of a scalable coating method that can be used for industrial manufacturing. This study investigated the combined cooperation of methylammonium acetate (MAAc) additive doping in a perovskite precursor solution and a mixed nonfullerene small-molecule semiconductor additive (DCDTT) in chlorobenzene for an antisolvent spraying treatment for the preparation of an ultrasonic spray-coated perovskite film. This spray-coating method forms densely arranged crystals and passivates the defect states located around the surface grain boundaries through additive engineering. The additives form an MAAc-based intermediate and DCDTT coordination interaction with Pb²⁺, increasing the film quality of the methylammonium lead iodide (MAPbI₃) perovskite. It was found that the addition of MAAc together with the antisolvent DCDTT treatment contributed to the enhanced crystallinity and reduced grain boundaries and trap states in perovskite films. These attributes result in a markedly higher power conversion efficiency (PCE) of 17.18% in the corresponding inverted perovskite solar cell than in the control device, with a PCE of 10.04%. The synergetic additive-modified perovskite devices retain ∼85% of the initial PCE after 7 days under ambient conditions. These observations point to a passivating effect by introducing additives while using a scalable spraying method for depositing perovskite films.