Restraining Photocurrent Loss of Lead-Free Perovskite Solar Cells by Regulating Surficial Hydroxyl of Fluorine-Doped Tin Oxide

The surface treatment of transparent conducting oxide substrates constitutes the initial step in fabricating solar cells. However, the specifics of this process are often oversimplified. This study delves into the impact of surface treatment on fluorine-doped tin oxide (FTO) substrates on the performance of Sn perovskite solar cells. Varied thicknesses of the coated poly(3,4-ethylenedioxythiophene)polystyrenesulfonate (PEDOT:PSS) layer were achieved by regulating the quantity of hydroxyl on FTO substrates. The investigation reveals that the thickness of the PEDOT:PSS layer directly influences the photoluminescence intensity and carrier lifetime, irrespective of the perovskite crystal quality. Thinner PEDOT:PSS layers are observed to mitigate shallow-level defects, thereby enhancing the short-circuit current density of solar cell devices. This study underscores the significance of controlling the heterostructure properties for improving solar cell performance.