Fabrications of Nb-doped TiO² (TNO) transparent conductive oxide polycrystalline films on glass substrates by sol-gel method

Anatase Ti_0.94Nb_0.06O₂ (TNO) films were fabricated on glass substrates by sol-gel method using a dipcoating technique. The annealing treatment was separated into two steps, first in air at 350-550 °C for 1 h and then in vacuum of 4.0 9 10^-4 Pa at 550 °C for 1 h. The influence of vacuum annealing treatment to the electrical and optical properties was discussed. Especially, the role of air annealing treatment from 350 to 550 °C on the crystallization and the structure of the films was analyzed. It is proved that the films annealed at 550 °C in air and then 550 °C in vacuum exhibited the minimum resistivity of 19.3 XΩcm and the average optical transmittance of about 75% in the visible range, indicating that the sol-gel method is a feasible and promising method to fabricate TNO films.