Inverted (p-i-n) perovskite solar cells have an advantage of low process temperature (<150 °C) compared to conventional (n-i-p) solar cells and are suitable for application to flexible solar cells. However, expensive and unstable fullerene derivatives are necessary as an electron collector. In this study, we developed TiO₂ coating process on perovskite materials at room temperature by solution process. The TiO₂ layers formed from TiI₄ precursor worked as an electron collector of perovskite and exhibited power conversion efficiency of 12.1%.