Room-Temperature-Processed ZrO2 Interlayer toward Efficient Planar Perovskite Solar Cells

The Sn-doped In2O3 transparent conductive [indium tin oxide (ITO)] electrode in planar perovskite solar cells (PSCs) is modified by a zirconia (ZrO2) interlayer with a low-temperature process. Here, the ZrO2 film is prepared by ultraviolet (UV) treatment at room temperature. The effects of the inserted ZrO2 interlayer on the performance of CH3NH3PbI3-xClx-based PSCs have been systemically studied. After optimizing the process, the champion efficiency of PSCs with a UV-treated ZrO2 interlayer is 19.48%, which is larger than that of the reference PSC (15.56%). The improved performance in the modified devices is primarily ascribed to the reduced trap states and the suppressed carrier recombination at the ITO/SnO2 interface. Our work provides a facile route to boost the photovoltaic performance of PSCs by modifying the surface of the transparent conductive electrode at room temperature.