Abstract
The sputtering technique is used to produce trigonal nickel oxide (NiO
0.96
) thin films doped with metallic copper. The films are crystalline, with crystallites preferentially growing on the (012) plane. The average crystallite size dropped from 287.2 Å to 237.7 Å, with a 10% increase in Cu content. After doping with metallic copper (4.2% Cu), the optical transmittance increases. However, the decrease in transmittance was caused by an excess in Cu content. The optical band gap of the base films was 3.902 eV, which decreased to 3.841 eV at 10% dopant of Cu. The refractive index, optical electronegativity, and optical dielectric constant were all calculated using the optical band gap. Because of the non-stoichiometric nickel oxide and the presence of copper, the films’ photoluminescence and color emission are observed in the blue region rather than brown color.