Studies on Metal-Oxide Semiconductor ZnO as a Hydrogen Gas Sensor

Author(s) C.S. Prajapati, P.P. Sahay
Affiliations Department of Physics, Motilal Nehru National Institute of Technology, Allahabad-211 004, India
Issue Volume 3, Year 2011, Number 1, Part 4
Dates Received 04 February 2011, in final form 14 October 2011, published online 17 October 2011
Citation C.S. Prajapati, P.P. Sahay, J. Nano- Electron. Phys. 3 No1, 714 (2011)
PACS Number(s) 73.90._f, 81.05.Dz
Key words Metal-oxide semiconductor (2) , Zinc oxide (9) , Hydrogen gas sensor, Structural properties (8) , Electrical properties (14) .
Metal-oxide semiconductor ZnO thin films were prepared on glass slides by spray pyrolysis technique at substrate temperature (410 ± 10) °C. Zn(NO3)26H2O was used as the precursor solution. The films thus prepared are undergone for structural and morphological studies using X-ray diffraction and scanning electron microscopy The films are found to be polycrystalline zinc oxide in nature, possessing hexagonal wurtzite crystal structure and nanocrystalline in grain size ~ 30-35 nm. The hydrogen sensing performance of the films has been investigated for various concentration of hydrogen in air at different operating temperatures in the range 200-400 °C. It is observed that the response is maximum (44.3 %) at the operating of temperature of 250 °C for 0.8 vol % concentration of hydrogen in air. A possible sensing mechanism for hydrogen has been proposed.