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Date of Publication:2012-01-01

Journal:无机材料学报

Affiliation of Author(s):电子信息与电气工程学部

Volume:27

Issue:05

Page Number:458-462

ISSN No.:1000-324X

Abstract:Rutile TiO2 based semiconductor-type sensors were investigated for sensing CO within the temperature range from 600 degrees C to 800 degrees C. The sensor showed p-type behavior to CO (20-2000 mg/m(3)) when tested in oxygen concentrations varied from 10% to 2% between 600 degrees C and 700 degrees C. The response of the sensor decreased significantly as the temperature increased from 600 degrees C to 700 degrees C approaching to one. However, when the temperature was above 750 degrees C, an n-type behavior of the sensor to CO was observed. This n-type response further increased when the temperature increased to 800 degrees C. AC impedance was employed to study the conduction behaviors of the TiO2 thick film in both varied oxygen concentrations and CO environment at 800 degrees C. The results indicate that the change of the oxygen ion/vacancy concentrations in the bulk TiO2 is probably the reason for the p-n conduction transition induced by CO.

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