ZnPc/CsPbBr3 QDs collaborative interface modification to improve the performance of CsPbBr3 perovskite solar cells

Carbon-based, all-inorganic CsPbBr 3 perovskite solar cells (PSCs) have attracted considerable interests because of their superior environmental stability, simple and low-cost fabrication process. However, the large energy barrier and high defect states at the CsPbBr 3 /Carbon interface will cause poor carrier extraction and serious carrier recombination, which further degrade performance of final devices. In this work, we introduce zinc phthalocyanine (ZnPc), CsPbBr 3 quantum dots (QDs), and ZnPc mixed CsPbBr 3 QDs in proper proportion as the CsPbBr 3 /carbon interface modification layers of CsPbBr 3 PSCs. It is found that the modification layers, especially the ZnPc mixed CsPbBr 3 QDs modification layer, can passivate trap states, improve interface contact and optimize energy level alignment at the CsPbBr 3 /carbon interface, which can further enhance carrier extraction, suppress carrier recombination and improve performance of final devices. By virtue of ZnPc mixed CsPbBr 3 QDs modification, a highest efficiency of 10.20% and long-term stability over 6 months has been achieved.