CO Gas Sensor Based on E-Beam Evaporated ZnO, MgZnO, and CdZnO Thin Films: A Comparative Study

• Published in: IEEE sensors journal Vol. 19; no. 7; pp. 2450 - 2457
• Main Authors: Punetha, Deepak, Pandey, Saurabh Kumar
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Cadmium; Carbon monoxide; CdZnO; Chromium; CO gas sensor; Comparative studies; E-beam evaporation; Electrical properties; Electron beams; Gas detectors; Gas sensors; II-VI semiconductor materials; MgZnO; Operating temperature; Optical properties; Optical sensors; Response time; Sensors; Silicon dioxide; Silicon substrates; Temperature sensors; thin film; Thin films; X-ray scattering; Zinc oxide; ZnO
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2018.2890007

This paper reports a comparative study of electron-beam evaporated ZnO, MgZnO, and CdZnO thin film based-gas sensor. At room temperature (RT), these semi-conductive thin films were deposited on Si/SiO 2 substrate and an interdigitated pattern of chromium electrode deposited on these films. Device properties, such as structural, optical, and electrical, have been reported and analyzed. The sensors have been tested at different operating temperatures. At 250 °C, the sensor shows the best response for CdZnO thin films. We have obtained sensor response 4.86 with response time 15 sec for 100-PPM carbon mono oxide (CO) gas concentration for CdZnO thin film. Based on experimental results, Cd-doped ZnO has been found most suitable among these semiconducting metal oxides, when used as a CO gas sensor. A correlation between structural, optical, and electrical properties with these thin films has also been established.