Mixed-phase Mesoporous TiO 2 Film for High Efficiency Perovskite Solar Cells

Mesoporous scaffold structures have played great roles in halide perovskite solar cells(PSCs), due to the excellent photovoltaic performance and commercial perspective of mesoporous PSCs. Here, we reported a mixed-phase TiO2 mesoporous film as an efficient electron transport layer(ETL) for mesoporous perovskite solar cells. Due to the improved crystal phase, film thickness and nanoparticle size of TiO2 layer, which were controlled by varying the one-step hydrothermal reaction time and annealing time, the PSCs exhibited an outstanding short circuit photocurrent density of 25.27 mA/cm2, and a maximum power conversion efficiency(PCE) of 19.87%. It is found that the ultra-high Jsc attributes to the excellent film quality, light capturing and excellent electron transport ability of mixed-phase TiO2 mesoporous film. The results indicate that mix-phase mesoporous metal oxide films could be a promising candidate for producing effective ETLs and high efficiency PSCs.