Cesium-Doped Vanadium Oxide as the Hole Extraction\nLayer for Efficient Perovskite Solar Cells

Abstract

In this study, we report the utilization\nof low-temperature solution-processed\nCs-doped VO_X thin films as the hole extraction layers (HELs)\nin perovskite solar cells (PSCs). It is found that the VO_X:<i>y</i>Cs (where <i>y</i> is the mole ratio\nof Cs versus V and <i>y</i> = 0.1, 0.3, and 0.5) thin films\npossess better electrical conductivities than that of the pristine\nVO_X thin film. As a result, the PSCs incorporated with\nthe VO_X:<i>y</i>Cs HEL exhibit large fill factors\nand high short-circuit currents, with consequently high power conversion\nefficiencies, which is more than 30% enhancement as compared with\npristine VO_X HEL. Our studies provide a facial way to enhance\nthe electrical conductivity of the hole extraction layer for boosting\ndevice performance of perovskite solar cells.