Improved efficiency of dye-sensitized solar cells aided by corn-like TiO2 nanowires as the light scattering layer

We present a new TiO2 morphology, featuring highly crystalline anatase structure, synthesized by a two consecutive hydrothermal operation for the manufacture of dye-sensitized solar cells (DSSCs). This construct is a one-dimensional (1D) nanostructure (i.e., nanowire) with interconnected nanoparticles on the surface with a large percentage of reactive facets, so called corn-like nanowire. Such morphology is produced by a surface modification concept using surface tension stress mechanism. The double layer DSSC made of anatase-TiO2 nanoparticles as the under-layer and corn-like TiO2 nanowires as the over-layer (as light scattering layer) shows higher conversion efficiency of 7.11% and short circuit current density of 16.54 mA/cm(2) than that of containing anatase-TiO2 nanoparticles as the under-layer and regular TiO2 nanowires as the over-layer. The novel TiO2 morphology enhances photon capture of fabricated DSSC by exerting a triple function mechanism including improvement of light scattering, dye sensitization and photo-generated charge carriers. An increase of 12% in cell efficiency is achieved by employment of corn-like structure as a result of slow charge recombination. The presented strategy demonstrates the feasibility of the new concept for improvement of cell efficiency by effective light management. (C) 2012 Elsevier Ltd. All rights reserved.