Influence of Applied Voltage on Anodized TiO₂ Nanotube Arrays and Their Performance on Dye Sensitized Solar Cells

Abstract

Highly ordered titanium dioxide (TiO2) nanotube films have been fabricated using anodic oxidation at different voltages (10 V to 70 V). The morphology, specific surface area, light absorbance capability and conductivity of the obtained films have been investigated. The anodized voltage was found to have a crucial influence on the morphology, light absorb capability and photo-electrochemical properties of the anodized nanotube films. The diameter of the nanotube increases linearly with the applied voltage. The nanotube film anodized at 30 V has the highest BET (Brunauer-Emmett-Teller) surface area, much more quantity of coated sensitizer N719, and the smallest resistance for dye sensitized solar cells (DSSC). Back side illuminated DSSC were assembled using these as-anodized nanotube films. Pt-FTO, which has a transmittance of about 50%, served as counter electrode. The best device based on nanotube films performed at 30 V gives a highest power conversion efficiency of 1.87%, with a photocurrent density (J(SC)) of 6.70 mA/cm2 and open circuit voltage (V(OC)) of 0.57 V.