NO₂ Sensing Characteristics of Thin Film TiO₂

Abstract

The rutile-type TiO₂ thin film doped with pentavalent additives such as Nb or Ta, prepared by a multi-target sputtering system, exhibited fairly good NO₂ sensing characteristics over the range from 0 to 300ppm at 600°C. According to the Arrhenius plots between conductivity and reciprocal temperature, it seems that the doped Nb or Ta formed some impurity energy level in the forbidden band of TiO₂, while V-doped film showed different conducting mechanism. In addition, high-temperature durability in oxydative and reductive exhaust gases was confirmed at 800°C.