Doping of a nanostructured titania thick film: structural and electrical investigations

Thick films of nanostructured pure TiO2, Nb/TiO2, Ga/TiO2, and Ta/TiO2 have been fabricated by screen-printing technology. Structural, morphological, and optical studies have been carried out in order to correlate the measurements to electrical performance. We showed that addition of dopants inhibits grain growth due to firing and hinders conversion of anatase to rutile. The films were characterised electrically in terms of conduction properties and grain-to-grain energy barrier. The films proved sensitive to CO and NO2. It was also shown that firing temperature and dopant content strongly influence the gas response of the films.