Structural, optical and electrical properties of chemically sprayed nanosized gallium doped CdO thin films

The effect of [Ga]/[Cd] ratio on the structural, morphological, optical and electrical properties of chemically sprayed Ga-doped CdO thin films is investigated. XRD studies reveal that the films are polycrystalline with cubic structure and exhibit (2 0 0) preferential orientation. It is inferred that the Ga3+ ions replace the lattice sites at lower concentrations and interstitial sites at high concentrations. There is considerable broadening of (2 0 0) peak and shift of Bragg's angle with respect to [Ga]/[Cd] ratio. The electrical studies confirm degenerate, n-type semiconductor nature of Ga-doped CdO thin films with minimum resistivity of 3.7 × 10−4 Ω cm. The optical gap varies from 2.27 to 2.44 eV due to Moss–Burstein effect. The highest figure of merit observed in the present study is 1.69 × 10−4 Ω−1. PL intensity of green emission around 470 nm has found to be increased with increase in [Ga]/[Cd] ratio.