Transparent conducting zinc oxide as anti-reflection coating deposited by radio frequency magnetron sputtering

Abstract

Highly transparent (visible transmission above 90%) and conducting ZnO:Al thin films with strong anti-reflection property have been prepared by reactive radio frequency (rf) magnetron sputtering under Ar + H2 ambient, substrate temperature at 300°C. H2 ratio in the Ar and H2 gas fed from 0 to 40%. The electrical resistivity and sheet resistance of ZnO:Al film are 2.8 × 10−4ohm-cm and less than 10Ω/□ respectively. The % reflectance (R) is significantly small (2% > R > 0.5%) in the wavelength range 1,000–1,500 nm and the refractive index (n) of the same ZnO:Al film is 1.49 at λ = 1,100 nm. All ZnO:Al films have orientation with good surface topography.