Enhancing Perovskite Solar Cell Performance through Surface Engineering of Metal Oxide Electron-Transporting Layer

Perovskite solar cells have gained increasing interest in recent times owing to the rapidly enlarged device efficiency and tunable optoelectronic properties in various applications. In perovskite solar cells, interface engineering plays an important role in determining the final device efficiency and stability. In this study, we adopted TiCl4 treatment to reduce the surface roughness of the metal oxide layer and improve the perovskite film quality to obtain better device performance. After proper TiCl4 treatment, the efficiencies of TiCl4–TiO2- and TiCl4–ZnO-based devices were significantly enhanced up to 16.5% and 17.0%, respectively, compared with those based on pristine TiO2 and ZnO (13.2% and 10.2%, respectively).