TiO₂ nanofiber solid-state dye sensitized solar cells with thin TiO₂ hole blocking layer prepared by atomic layer deposition

We incorporated a thin but structurally dense TiO₂ layer prepared by atomic layer deposition (ALD) as an efficient hole blocking layer in the TiO₂ nanofiber based solid-state dye sensitized solar cell (ss-DSSC). The nanofiber ss-DSSCs having ALD TiO₂ layers displayed increased open circuit voltage, short circuit current density, and power conversion efficiency compared to control devices with blocking layers prepared by spin-coating liquid TiO₂ precursor. We attribute the improved photovoltaic device performance to the structural integrity of ALD-coated TiO₂ layer and consequently enhanced hole blocking effect that results in reduced dark leakage current and increased charge carrier lifetime.