ZnO thin films for VOC sensing applications

ZnO thin films were prepared by reactive RF sputtering on thermally oxidized Si for gas sensing applications. Three VOC vapors were chosen to investigate the response behavior of the prepared ZnO. Acetone, isopropanol and ethanol were tested, and the sensitivity of the sensor toward acetone was the highest (S similar to 100) for 500 ppm acetone at 400 degrees C. The largest sensitivity was achieved at 400 degrees C for all the above vapors. The sensor shows a stable, reversible and repeatable behavior in the acetone concentration ranging from 15 up to 1000 ppm. The mechanism of the sensing was explained according to the ion-osorption model. (C) 2010 Elsevier Ltd. All rights reserved.