In situ topological transformation of hierarchical TiO2 hollow nanobricks as efficient scattering layer for dye-sensitized solar cells

Abstract NH4TiOF3 nanobricks are prepared by a one-step hydrothermal route and then are made into paste. The NH4TiOF3 are in situ topologically transformed into anatase TiO2 hollow nanobricks via a boric acid treatment process after the paste is screen-printed onto FTO glass as a scattering layer for DSSCs. The cell with scattering layer exhibits a high photovoltaic conversion efficiency of 8.09%, which is 24.8% higher than that of the cell composed of bare nanocrystalline TiO2 (6.48%). After a series of characterization, the higher specific surface area and the superior light-scattering ability of hierarchical TiO2 hollow nanobricks are proved to be the main facts for the enhanced efficiency.