Study of cobalt doping on the electrical and optical properties of titanium dioxide thin film prepared by sol-gel method

Undoped Nanostructured Titanium Dioxide thin film (UN) and Cobalt doped nanostructured (CoDN) TiO₂ thin film has successfully prepared using sol-gel method and deposited onto silicon and glass substrate by spin coating technique. Nanostructured TiO₂ thin film were prepared at 0.1 M, 0.2 M, 0.3 M and 0.4 M, Co doped TiO₂ thin film was prepared with additional of ion Co at 1 at%. The electrical and optical properties of the UN TiO₂ thin films and CoDN TiO₂ thin film has successfully studied. The electrical properties indicates that both 0.2 M of UN TiO₂ thin film and CoDN TiO₂ thin film gives low of resistance compare to other sol-gel concentration. As we compared both UN TiO₂ thin film and CoDN TiO₂ thin film, the lowest resistance comes from Cobalt doped TiO₂ thin film. For optical properties, CoDN TiO₂ thin film gives the highest percentage of transmittance, which is above 80% in visible region (450-1000 nm). As for band gap energy, there is decreasing in band gap energy compared from UN TiO₂ thin film to CoDN TiO₂ thin film.