Dual-Protection Strategy for High-Efficiency and Stable CsPbI<sub>2</sub>Br Inorganic Perovskite Solar Cells
Sheng Fu, Wenxiao Zhang, Xiaodong Li, Li Wan, Yulei Wu, Lijun Chen, Xiaohui Liu, Junfeng Fang
Abstract
Large opening circuit voltage (Voc) loss and poor moisture stability have significantly hindered the progress of inorganic perovskite solar cells (IPSCs). Here, we report a dual-protection strategy via incorporating monomer trimethylolpropane triacrylate (TMTA) into CsPbI2Br perovskite bulk and capping the surface with 2-thiophenemethylammonium iodide (Th−NI) to ameliorate the above issues. Benefiting from growth control and effective suppression of both bulk and surface recombination, the resulting devices show a great improved efficiency from 12.17 to 15.58% with a champion Voc of 1.286 V. Also, the dual-protection strategy endows films with promoted moisture tolerance, and the nonencapsulated device retains 83.4% of its initial efficiency after aging at 25% relative humidity for 1540 h. More importantly, the target device shows good operational stability and reveals the unfallen efficiency after maximum power point tracking for 350 h at 45 °C. Our work offers a feasible method to fabricate efficient and stable CsPbI2Br IPSCs for future commercialization.