A holistic sunscreen interface strategy to effectively improve the performance of perovskite solar cells and prevent lead leakage

The stability and lead leakage of perovskite solar cell (PSC) are two obstacles to its commercialization. Herein, a holistic interface modification strategy has been proved to effectively improve the performance and stability of PSC and prevent lead leakage by modifying the relevant interface between functional layers including perovskite layer and charge transport layer. Through systematic research, it is found that the tautomeric BZP molecules can slow down the degradation of perovskite by UV light and adjust the energy level arrangement between the interfaces, while the strong coordination between the water-insoluble PBSA and Pb2+ ions is helpful to passivate perovskite surface defects and prevent Pb2+ ions from leaking into the environment. Consequently, an impressive efficiency of 24.14% (0.09 cm2) and a module efficiency of 17.36% (19.32 cm2) is successfully obtained based-on our holistic interface modification strategy, along with slight hysteresis and improved UV tolerance. More importantly, the lead leakage of the optimized solar module has also been effectively suppressed due to the excellent absorption capacity of PBSA to the leaked Pb2+ ions. Meanwhile, the T90 and T80 lifetime of the optimized solar module also exceed 1130 h and 2000 h, respectively, under continuous light illumination.