Structure, morphology and optical properties of nanocrystalline gallium oxide thin films
Gallium Oxide thin films were produced by sputter deposition by varying the substrate temperature (Ts) in a wide range (Ts=25-800 °C) and under variable deposition time. 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 = 300–700 °C. The spectral transmission of the films increased with increasing temperature. The band gap of the films varied from 4.96 eV to 5.17 eV for a variation in Ts in the range 25–800 °C for samples deposited for 30 minutes and it varied from 4.98 eV to 5.09 eV for a variation in Ts in range of 400-800 °C. A relationship between microstructure and optical property is discussed.
Samala, Sampath Kumar, "Structure, morphology and optical properties of nanocrystalline gallium oxide thin films" (2012). ETD Collection for University of Texas, El Paso. AAI1533251.