Performance of TiO2 films obtained by cathodic arc deposition as carbon monoxide gas sensor

A. MÁRQUEZ; A. KLEIMAN; D. G. LAMAS

Conferencia; Twefth Int. Cof. on Plasma Surface Engineering; 2010

In this work TiO2 thin films prepared by CAD on glass and silicon substrates were characterized toward its implementation in gas sensors. The films were grown in an oxygen environment (~2 Pa) employing a 100 A continuous arc. They were synthesized at 400 ºC and at room temperature. The films obtained at 400 ºC grew mainly in anatase phase with the presence of small quantities of rutile phase, while films synthesized at room temperature resulted amorphous and were crystallized in anatase phase with a post-annealing at 400 ºC. The crystal structure of the films was studied by x-ray diffraction in the glancing angle geometry, the morphology was observed by atomic force microscopy and reflectance measurements in the visible range were also performed. The film electrical conductivity was investigated at room temperature and in the temperature range 400~500°C in air and with CO concentrations varying from 20 to 200 ppm.