ELECTRICAL-PROPERTIES OF SOL-GEL-DERIVED TRANSPARENT TITANIA FILMS DOPED WITH RUTHENIUM AND TANTALUM

Transparent conductive TiO2 films doped with Ru and Ta were prepared o n SiO2 glass substrates by the sol-gel method using Ti(OC3H7i)(4) solu tions with HCl, HNO3 or diethanolamine (DEA) as a catalyst. The films were anatase when HCl or HNO3 was added to the solution. The solution preparation condition, solution composition, dopant content and hear-t reatment temperature all affected the electrical resistivity of the re sultant films. There was a clear tendency for the film resistivity to become lower when the dopant solution was refluxed and HCl was used as the additive. The resistivity decreased with increasing Ta content, b ut decreased with increasing Ru content. Most of the films showed resi stivity minima at a heat-treatment temperature of 700 degrees C. The l owest resistivity of 10 similar to 100 Ohm cm was attained when only T a was used as a dopant. (C) 1998 Elsevier Science S.A.