Bifunctional Passivation through Fluoride Treatment for Highly Efficient and Stable Perovskite Solar Cells

作者：Chang Liu, Jiyao Zhang, Luozheng Zhang, Xianyong Zhou, Yanliang Liu, Xingzhu Wang, Baomin Xu · 发表于：Advanced Energy Materials · 年份：2022 · DOI：10.1002/aenm.202200945 · 被引用次数：59 · 研究领域：Perovskite Materials and Applications、Chalcogenide Semiconductor Thin Films、Conducting polymers and applications

Abstract Due to the low formation energy, surface defects are more likely to form on the surface of TiO 2 films, resulting in a decline in the efficiency and stability of perovskite solar cells (PSCs). Additionally, defects on the bottom surface of the perovskite layer in contact with TiO 2 play a key role in V oc (open circuit voltage) loss and the PSC degradation process. Therefore, to improve the efficiency and stability of PSCs, it is critical to develop a reproducible and low‐cost method for passivating the defects on both the TiO 2 surface and on the bottom surface of the perovskite layer. In this work, fluoride is utilized as a bifacial contact passivation agent for decreasing the number of defects on the TiO 2 surface and the bottom surface of the perovskite layer. PSC efficiency can be significantly increased from 21.3% to 23.7% with fluoride passivation. In addition, the long‐term stability of PSCs, especially light irradiation stability, can be markedly improved. The passivation effects of fluoride treatment on TiO 2 films are studied by theoretical calculation and experimental characterization. This work provides a thorough understanding of the TiO 2 /perovskite interface and demonstrates an approach for improving the efficiency and stability of PSCs.