Synthesis of TiO₂ nanoframe and the prototype of a nanoframe solar cell

Nanoframes containing 20nm diameter TiO2 nanowire arrays were synthesized with polymer templates via cathodic sol-gel deposition followed by 450 °C sintering. Raman spectra indicated that they are composed of pure anatase TiO2. The nanowire array inside the nanoframe was confirmed to be single crystalline by high resolution TEM. Dye-sensitized solar cells based on this nanoframe were fabricated and the effects of the top cover in the nanoframe, which is the only difference between nanoframe cells and nanowire cells, were investigated. The results show that the top cover does not prevent the I- and I3- ions underneath from diffusing freely in the electrolyte and causes no deterioration of the cell performance. The nanoframe cell is a promising device in which nanowire arrays are strengthened and the effective internal surface area has the potentiality to be increased without sacrificing the advantages of nanowire cells compared to nanoparticle cells. © 2010 IOP Publishing Ltd.