EFFECT OF NB, CR, SN ADDITIONS ON GAS-SENSING PROPERTIES OF TIO2 THIN-FILMS

The effect of Nb and Cr dopants as well as Sn4+ additions on the elect ronic structure of rf-sputtered TiO2 thin films and its subsequent inf luence on gas sensor performance is reported. The changes in the elect rical conductivities of TiO2 thin films doped with up to 10 at.% Nb, 4 at.% Cr and TiO2-SnO2 in the full range of compositions upon exposure to hydrogen and oxygen are demonstrated. The spectral dependence of t he absorption coefficient in the vicinity of the band gap transition o f TiO2 is shown to be affected by doping. (C) 1997 Elsevier Science S. A.