Growth and properties of Ti films formed by dc magnetron sputtering for TCO-free photo electrode applications

Porous Titanium (Ti) films were fabricated using dc magnetron sputtering (DMS) technique on a nanoporous TiO2 layer prepared by sol-gel combustion (SGC) method; films were investigated with respect to their photoanode properties of TCO-free DSCs. The sheet resistivity of porous Ti films was enhanced with substrate temperatures increasing in the range of 150°C–300°C. The porous Ti layer of 8.5 µm thickness deposited at substrate temperature of 250°C has a lower sheet resistivity (∼1.9 Ω/sq.) compared to that of FTO. The porous Ti layer, with highly ordered columnar structure prepared by 5 mTorr sputtering at substrate temperature of 250°C, shows good impedance and conversion efficiency (FF: 0.68, V oc : 0.69V, J sc : 11.47 mA/cm2, η: 5.38%).