Investigation of the Carbon Monoxide Gas Sensing Characteristics of Tin Oxide Mixed Cerium Oxide Thin Films

• Main Authors: Muhammad B. Haider, Mohammad F. Al-Kuhaili, Imran A. Bakhtiari, Sardar M. A. Durrani
• Format: Article
• Language: English
• Published: MDPI AG 2012-02-01
• Series: Sensors
• Subjects: thin film; AFM; XPS; CeO2; SnO2; CO sensor; semiconductor gas sensor
• Online Access: http://www.mdpi.com/1424-8220/12/3/2598/

Thin films of tin oxide mixed cerium oxide were grown on unheated substrates by physical vapor deposition. The films were annealed in air at 500 °C for two hours, and were characterized using X-ray photoelectron spectroscopy, atomic force microscopy and optical spectrophotometry. X-ray photoelectron spectroscopy and atomic force microscopy results reveal that the films were highly porous and porosity of our films was found to be in the range of 11.6–21.7%. The films were investigated for the detection of carbon monoxide, and were found to be highly sensitive. We found that 430 °C was the optimum operating temperature for sensing CO gas at concentrations as low as 5 ppm. Our sensors exhibited fast response and recovery times of 26 s and 30 s, respectively.