Materials Sciences and Applications, 2018, 9, 844-857 http://www.scirp.org/journal/msa ISSN Online: 2153-1188 ISSN Print: 2153-117X DOI: 10.4236/msa.2018.910061 Sep. 29, 2018 844 Materials Sciences and Applications Synthesis and Characterization of Metal Organic Chemical Vapour Deposited Chromium Doped Zinc Oxide Thin Film for Gas Sensing Applications Olumide Oluwole Akinwunmi 1* , Olakunle A. Akinwumi 1 , Johnson Ayodele O. Ogundeji 1 , Adetokunbo Temitope Famojuro 2 1 Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, Nigeria 2 Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria Abstract Chromium (Cr) doped Zinc oxide ZnO thin films were deposited onto glass substrates by Metal Organic Chemical Vapour Deposition (MOCVD) tech- nique with varying dopant concentration at a temperature of 420˚C. The effect of the chromium concentration on morphological, structural, optical, electrical and gas sensing properties of the films were investigated. The scanning elec- tron microscopy results revealed that the Cr concentration has great influence on the crystallinity, surface smoothness and grain size. X-ray diffraction (XRD) studies shows that films were polycrystalline in nature and grown as a hexagonal wurtzite structure. A direct optical band energy gap of 3.32 to 3.10 eV was obtained from the optical measurements. The transmission was found to decrease with increasing Cr doping concentration. Rutherford Back- scattering Spectroscopy (RBS) analysis also demonstrates that Cr ions are substitutionally incorporated into ZnO. I-V characteristic of the film shows a resistivity ranges from 1.134 × 10 -2 Ω cm to 1.24 × 10 -2 Ω cm at room temper- ature. The gas sensing response of the films were enhanced with incorporation of Cr as a dopant with optimum operating temperature around 200˚C. Keywords Zinc Oxide, Thin Films, Metal Organic Chemical Vapour Deposition, Gas Sensors 1. Introduction ZnO has been found invaluable in the development of new technologies based How to cite this paper: Akinwunmi, O.O., Akinwumi, O.A., Ogundeji, J.A.O. and Famojuro, A.T. (2018) Synthesis and Cha- racterization of Metal Organic Chemical Vapour Deposited Chromium Doped Zinc Oxide Thin Film for Gas Sensing Applica- tions. Materials Sciences and Applications, 9, 844-857. https://doi.org/10.4236/msa.2018.910061 Received: August 30, 2018 Accepted: September 26, 2018 Published: September 29, 2018 Copyright © 2018 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access