Highly efficient dye-sensitized solar cells of thick mesoporous titania films derived from supramolecular templating

Thick titania films of highly ordered orthorhombic pore organization and sufficient thickness up to a few micrometers have been synthesized via a supramolecular templated route and layer-by-layer deposition. An appropriate pre-heat treatment was applied to improve the mesopore accessibility. The mesoporous films were highly crystallized with the crystallite size of approximately 12 nm regardless of the film thickness, due to the spatial confinement of mesopores. A high optical transparency was demonstrated for the mesoporous films, which is ascribed to the high mesoporosity and uniformity of the ordered film structure. Both the mesopore accessibility and optical transparency have contributed to the high performance of these films as photoanodes in the dye-sensitized solar cells, showing a maximum solar energy conversion efficiency of 6.02% for a film of 5.08 microm in thickness.