Tailoring the textured surface of porous nanostructured NiO thin films for the detection of pollutant gases

• DOI: 10.1016/j.tsf.2015.04.004
• Publication Date: 2015-04-11T09:44:57Z
• Authors: R. Kumar; C. Baratto; G. Faglia; G. Sberveglieri; E. Bontempi; L. Borgese
• Keywords: Non-blocking I/O; Oxidizing agent; Nickel oxide

In the present article, an experimental approach to detect pollutant gases in presence of humidity was applied for gas sensors based on p-type NiO thin films. NiO thin films were deposited by radio frequency magnetron sputtering in inert atmosphere using a NiO target. Thin films were investigated by scanning electron microscopy to observe their surface morphology. Crystal structure and vibrational study were investigated by X-ray diffraction and micro-Raman spectroscopy, respectively. It was observed that deposition temperature played a crucial role in the structural and surface morphology of NiO thin films. Sensing response of the nanostructured thin films to reducing and oxidizing gas was studied as a function of gas concentration and operating temperature. A double digit (12.3) response was observed towards ozone at 200 degrees C, while maximum response to ethanol and acetone was recorded at 400 degrees C. A correlation was established between sensing response and crystalline dimension for ozone sensing. The result showed that NiO thin films can be used as p-type metal oxide material for the fabrication of solid state gas sensors to detect low concentrations of ozone (70 ppb). (C) 2015 Published by Elsevier B.V.