A selective ethanol gas sensor based on spray-derived Ag–ZnO thin films
A simple and cost-effective spray pyrolysis technique was employed to synthesize silver-doped zinc oxide (Ag–ZnO) thin films on the glass substrates from aqueous solutions of zinc acetate and silver nitrate precursors at 450 °C. The effects of Ag doping on structural, morphological, and gas-sensing properties of films were examined. The X-ray diffraction spectra of the Ag–ZnO films showed the polycrystalline nature having hexagonal crystal structure. Scanning electron microscopy (SEM) images of the pure ZnO films revealed the uniform distribution of the spherical grains (~80 nm size). Tiny Ag nanoparticles are clearly visualized in the SEM of Ag–ZnO films. The investigation of the effect of Ag doping on the gas-sensing properties of the Ag–ZnO revealed that the 15 % Ag-doped ZnO sample has the highest gas sensitivity (85 %) and excessive Ag doping in ZnO degraded the gas sensitivity. A possible mechanism of Ag–ZnO-based sensor sensitivity to the target gas is also proposed.
KeywordsEthanol Vapor Spray Pyrolysis Technique Dynamic Response Transient Zinc Acetate Precursor Solution
This work was partially supported by the Core Technology Development Program for Next-Generation Solar Cells of Research Institute for Solar and Sustainable Energies (RISE), GIST and the Human Resource Development of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) Grant funded by the Korea Government Ministry of Knowledge Economy (No. 20124010203180).
- 33.Moulder JF, Stickle WF, Sobol PE, Bomben KD (1992) Handbook of X-ray photoelectron spectroscopy. Perkin-Elmer, Eden PrairieGoogle Scholar
- 42.Basu S, Basu PK (2009) J Sens 2009:861968Google Scholar