Effects of TiCl4 post-treatment on the performance of hole transport material-free, screen printable mesoscopic perovskite solar cells with carbon electrode

The prevention of current leakage in perovskite solar cells is an effective method for improving performance of devices. In this work, we treated a surface of TiO2 compact layer by the way of hydrolyzing TiCl4 aqueous solution and have investigated the influence of TiCl4 post-treatment on the performance of hole transport material-free, screen printable mesoscopic perovskite solar cells with carbon electrode. The device, which fabricated by TiO2 compact layer post-treated with TiCl4 aqueous solution for 50 min, has achieved highest device performance, with a short-circuit current density of 23.28 mA cm(-2), an open circuit voltage of 0.98 V, a fill factor of 0.65 and the power conversion efficiency of 14.83%. The improved device performance is attributed to inhibition of charge recombination at the fluorine-doped tin oxide/perovskite interface and improvement of charge transport ability of the TiO2 compact layer by TiCl4 post-treatment.