Study of Structural, Morphological, Optical and Electrical Properties of Spray-Deposited Gallium Oxide Thin Films: A Comparative Approach

Gallium oxide thin films were deposited onto the quartz substrate by chemical spray pyrolysis technique. The effect of annealing over the structural, morphological, optical and electrical properties of Ga2O3 thin films was studied. It was found that annealed Ga2O3 thin film had polycrystalline nature with beta-phase. Atomic force micrograph displayed formation of spherical particles over the film surface. A water contact angle study revealed that the annealed film had a hydrophobic nature due to its high surface roughness. Annealed films had high optical transparency (>90%) in visible region and estimated band gap was 4.66 eV. Other optical parameters namely extinction co-efficient, refractive index and dielectric constant were estimated and discussed for both as-deposited and annealed films. The annealed film had less electrical resistivity when compared to the as deposited one. Moreover, Nyquist plot revealed that both crystallite and crystallite boundary effect are equally influenced the AC impedance characteristics of annealed beta-Ga2O3 thin film.