Controlled synthesis of one-dimensional titania nanostructure films on transparent conductive glasses from a heterogeneous solvothermal method

Vertically oriented one-dimensional (1D) semiconductor wide bandgap nanostructures on transparent conducting substrates have recently attracted increasing interest due to their potential applications in dye-sensitized solar cells (DSSCs) [1, 2]. Hydrothermal method is very useful for the fabrication of aligned high crystallinity 1D nanowire or nanorod arrays such as ZnO nanowire arrays at low temperature. Compared to ZnO, TiO₂ nanowire arrays are much more difficult to be anisotropically grown on different substrates due to their tetragonal crystal structure. In order to vertically oriented grow TiO₂ on transparent conducting substrates in the solution, proper ions are required to adsorb on (110) facets of TiO₂ to accelerate the growth in the [001] direction [3]. In this paper, we report on the synthesis of 1 D TiO₂ nanostructure films on fluorine-doped tin oxide (FTO) substrates via an interface reaction of nonpolar solvent and hydrophilic FTO glass substrate under solvothermal conditions.