Effects of Oxygen Flow Rates on the Physical Characteristics of Magnetron Sputtered Single-Phase Polycrystalline Cu₂O Films

The single-phase polycrystalline copper oxide (Cu₂O) films were prepared on sapphire substrates by radio frequency (RF) magnetron sputtering technology which was characterized by low cost and high efficiency. The influences of oxygen flow rate on physical characteristics of the prepared films were investigated. The XRD results showed that the single-phase Cu₂O film exhibited a (110) preferred orientation through the analysis of texture coefficient. The AFM images exhibited that the prepared Cu₂O film had the highest surface roughness with a distinctive quadrangular surface morphology. The optical transmittance of the single-phase Cu₂O film was under 35% and the band gap energy was calculated to be 2.30 eV, the absorption spectra included the peak wavelength of solar radiation and the high absorptivity made it to be a suitable absorbing material. The Hall measurement indicated that all the samples exhibited p-type conductivity. The resistivity, mobility and carrier concentration of the single-phase Cu₂O film was 4625 Ω·cm, 1.87 cm²/v·s and 7.227×10¹⁴ cm⁻³, respectively.

Keywords:
Magnetron sputtering; Cu₂O films; Oxygen flow rate; P-type semiconductor