Deposition and Optical Characterization of Sputter Deposited p-Type Delafossite CuGaO2 Thin Films Using Cu2O and Ga2O3 Targets

Materials (Basel). 2024 Apr 1;17(7):1609. doi: 10.3390/ma17071609.

Abstract

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.

Keywords: CuGaO2; RF Sputtering; SEM; TCO; XPS; XRD; delafossite; optical bandgap; optical transmission; p-type; transparent conducting oxides.

Grants and funding

This research received no external funding.