Enhancing the filling of perovskite material in the scaffold layer to improve the conversion efficiency of printable perovskite solar cells

The complete filling of perovskite materials into mesoporous TiO₂/ZrO₂ scaffold film remains a great challenge for achieving a high conversion efficiency in printed mesoscopic perovskite solar cells. However, there is a lack of a precise understanding of the filling dynamics to guide the optimization process. In this study, a process comprising the beginning infiltration step and the subsequent crystallization step have been proposed to optimize filling behavior. By introducing macropores in the first step using the polystyrene microsphere templating method to facilitate the infiltration of the perovskite precursor solution, combined with the bottom-up controlled crystallization assisted by a low-pressure gas pumping method in the second step, the perovskite material is more completely filled into the TiO₂/ZrO₂ scaffold layer. The photovoltaic performance of the perovskite solar cell shows that the conversion efficiency is improved by 375% compared to the weakly filled solar cells. This work contributes to enhance the filling of perovskite material and improve the conversion efficiency of printable perovskite solar cells.