Deposition and Optical Characterization of Sputter Deposited p-Type Delafossite CuGaO₂ Thin Films Using Cu₂O and...

CuGaO₂ thin films were deposited using the RF magnetron sputtering technique using Cu₂O and Ga₂O₃ targets. The films were deposited at room temperature onto a quartz slide. The sputtering power of Cu₂O remained constant at 50 W, while the sputtering power of Ga₂O₃ 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 Ga₂O₃ sputtering power of 175 W annealed at 900 °C revealed the development of nearly single-phase delafossite CuGaO₂ 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.