Liquefied petroleum gas sensing properties of sprayed nanocrystalline zinc oxide thin films

• Published in: Sensors and actuators. A. Physical. 2013-01, Vol.189, p.339-343
• Main Authors: Gaikwad, Rajendra S., Patil, Gauri R., Pawar, Bhagwat N., Mane, Rajaram S., Han, Sung-Hwan
• Format: Article
• Language: English
• Subjects: Detection; Liquefied petroleum gas; LPG; LPG sensors; Morphological evolution; Nanocrystals; Operating temperature; Optical studies; Structural elucidation; Thin films; Wurtzite; Zinc oxide
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2012.10.005

► Uniform, adherent nano-crystalline ZnO thin films by simple spray pyrolysis deposition technique. ► X-ray diffraction spectra reveals c-axis oriented wurtzite crystal with crystallite size of approximately 32–39nm. ► The absorbance has decreased and increase in band gap energy value after heat treatment. ► The LPG sensing performance of the films has been investigated at various concentrations in air at operating temperatures varying from 150 to 450°C. ► A maximum response was obtained for a nanocrystalline ZnO at 0.8vol% LPG gas in the air at 255°C temperature. A ZnO nanocrystalline detector for the liquefied petroleum gas (LPG) species is described. The nanocrystalline ZnO thin films were synthesized using a spray pyrolysis chemical deposition method and applied for structural elucidation, morphological evolution studies. The films are nanocrystalline (about 32–39nm crystallites sizes), hexagonal wurtzite crystal structure with c-axis orientation along (002) plane. The lattice stress developed with increase in temperature ensures decrease in lattice parameters. Enhanced band gap of the film with heat treatment is a key factor for generating the active sites for the sensing of gas species. The LPG sensing performances of the ZnO films have been investigated at various concentrations at operating temperatures varying from 150 to 450°C. A possible reaction mechanism of LPG sensing has also been proposed.