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 TiO ₂ 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/cm² 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.