Construction of Polyoxometalate‐Based Material for Eliminating Multiple Pb‐Based Defects and Enhancing Thermal Stability of Perovskite Solar Cells
Wei Wang, Jian Zhang, Kaifeng Lin, Yayu Dong, Jiaqi Wang, Boyuan Hu, Jiao Li, Zhe Shi, Yanjing Hu, Wei Cao, Debin Xia, Ruiqing Fan, Yulin Yang
Abstract
Abstract The high‐quality perovskite film with few defects plays an important role in the power conversion efficiency (PCE) and long‐term stability of perovskite solar cells. Here, an efficient strategy is proposed to eliminate Pb 0 and passivate Pb 2+ simultaneously by employing a stable polyoxometalate‐based material CoW 12 @MIL‐101(Cr) in the precursor solution of perovskite. The controllable oxidation ability of CoW 12 is optimized through the interaction with metal–organic frameworks, resulting in a doped perovskite film with regular morphology, large grain size, and low defects density. The solvent effects and formation of intermediate materials in the precursor solution are further investigated by an in situ thermogravimetry‐Fourier transform infrared spectroscopy analysis. In addition, the champion doped‐device showed enhanced PCE to 21.39% and excellent stability, maintaining 85% and 89% of the original PCE after heating at 85 °C in N 2 atmosphere and stored in ambient conditions (25 °C, 40% humidity) for 1000 h, respectively.