Structure, morphology, and optical properties of amorphous and nanocrystalline gallium oxide thin films

S. Sampath Kumar, E. J. Rubio, M. Noor-A-Alam, G. Martinez, S. Manandhar, V. Shutthanandan, S. Thevuthasan, C. V. Ramana

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    Abstract

    Gallium oxide (Ga2O3) thin films were produced by sputter deposition by varying the substrate temperature (Ts) in a wide range (Ts = 25-800 °C). The structural characteristics and optical properties of Ga2O3 films were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Rutherford backscattering spectrometry (RBS), and spectrophotometric measurements. The effect of growth temperature is significant on the chemistry, crystal structure, and morphology of Ga2O 3 films. XRD and SEM analyses indicate that the Ga2O 3 films grown at lower temperatures were amorphous, while those grown at Ts ≥ 500 °C were nanocrystalline. RBS measurements indicate the well-maintained stoichiometry of Ga2O3 films at Ts = 300-800 °C. The spectral transmission of the films increased with increasing temperature. The band gap of the films varied from 4.96 to 5.17 eV for a variation in Ts in the range 25-800 °C. A relationship between microstructure and optical property is discussed.

    Original languageEnglish
    Pages (from-to)4194-4200
    Number of pages7
    JournalJournal of Physical Chemistry C
    Volume117
    Issue number8
    DOIs
    Publication statusPublished - 11 Mar 2013

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    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Energy(all)
    • Physical and Theoretical Chemistry
    • Surfaces, Coatings and Films

    Cite this

    Kumar, S. S., Rubio, E. J., Noor-A-Alam, M., Martinez, G., Manandhar, S., Shutthanandan, V., Thevuthasan, S., & Ramana, C. V. (2013). Structure, morphology, and optical properties of amorphous and nanocrystalline gallium oxide thin films. Journal of Physical Chemistry C, 117(8), 4194-4200. https://doi.org/10.1021/jp311300e