Deposition and Optical Characterization of Sputter Deposited p-Type Delafossite CuGaO Thin Films Using CuO and GaO Targets.

CuGaO thin films were deposited using the RF magnetron sputtering technique using CuO and GaO targets. The films were deposited at room temperature onto a quartz slide. The sputtering power of CuO remained constant at 50 W, while the sputtering power of GaO was systematically varied from 150 W to 200 W. The films were subsequently subjected to annealing at temperatures of 850 °C and 900 °C in a nitrogen atmosphere for a duration of 5 h. XRD analysis on films deposited with a GaO sputtering power of 175 W annealed at 900 °C revealed the development of nearly single-phase delafossite CuGaO thin films. SEM images of films annealed at 900 °C showed an increasing trend in grain size with a change in sputtering power level. Optical studies performed on the film revealed a transmission of 84.97% and indicated a band gap of approximately 3.27 eV. The film exhibited a refractive index of 2.5 within the wavelength range of 300 to 450 nm.