Electrodeposited Ultrathin TiO2 Blocking Layers for Efficient Perovskite Solar Cells

In this study, the electrodeposition (ED) of ultrathin, compact TiO(2) blocking layers (BLs) on fluorine-doped tin oxide (FTO) glass for perovskite solar cells (PSCs) is evaluated. This bottom-up method allows for controlling the morphology and thickness of TiO(2) films by simply manipulating deposition conditions. Compared with BLs produced using the spin-coating (SC) method, BLs produced using ED exhibit satisfactory surface coverage, even with a film thickness of 29 nm. Evidence from cyclic voltammetry shows that an ED BL suppresses interfacial recombination more profoundly than an SC BL does, consequently improving the photovoltaic properties of the PSC significantly. A PSC equipped with an ED TiO(2) BL having a 13.6% power conversion efficiency is demonstrated.