Dye adsorption on atomic layer deposited aluminum oxides for tin-oxide-based dye sensitized solar cells

•Atomic layer deposition of Al2O3 improved the efficiency of SnO2 based dye-sensitized solar cells.•More dye absorption was one of the reasons for the high cell efficiency.•The process parameters in atomic layer deposition played essential role on dye absorption in the mesoporous.

In this paper, the mesoporous SnO2 photoelectrodes were coated by ultra-thin alumina through atomic layer deposition (ALD) technique to improve the solar cell efficiency. We find that an ultra-thin Al2O3 coated on mesoporous SnO2 photoelectrodes can improve the open-circuit voltage, short-circuit current, and fill factor, leading to the increase of the energy conversion efficiency. After the measurement by ultraviolet spectrometer in detail we conclude that the enhanced adsorption of the dye N719 after the aluminum oxide coating SnO2 is one of the main reasons to promote the cell efficiency.