摘要
Current density-voltage(J-V) hysteresis issue caused by unbalanced charge transport has greatly limited the improvement of power conversion efficiency(PCE) of halide perovskite solar cells(PSCs). Herein, hollow TiO2 mesoporous electron transport layer(ETL) was used to fabricate PSCs. The structure-dependent charge collection as well as its effect on PCE and hysteresis impactor(HI) of PSC were investigated. The results demonstrate that TiO2 hollow spheres in a size of around 50 nm (HS-50) can form a high quality perovskite/ETL interface with a less trap density. Moreover, the hollow TiO2 with the thin shell can help promote the extraction of electrons from perovskite layer to ETL, so as to reduce the charge accumulation and recombination at the perovskite/ETL interface and alleviate the hysteresis behavior. As a result, PSCs with HS-50 TiO2 delivered a champion PCE of 16.81% with a small HI of 0.0297, indicating a better performance than the commercial P25(PCE of 15.87%, HI of 0.2571).
基金
This work was supported by the National Natural Science Foundation of China (Nos.21931012,52022097)
the Beijing Natural Science Foundation,China (No.2202055)
the Foundation of the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020048).
