Tailoring the resonance wavelength and loss of highly Ga doped ZnO plasmonic materials by varied doping content and substrate temperature

In this paper, Ga-doped ZnO (GZO) thin films are deposited on glass substrates by radio frequency magnetron sputtering for low loss plasmonic applications. The effects of Ga2O3 content in the target and substrate temperature on the electrical, structural and optical properties of GZO films are investigated. Film with the highest carrier concentration of 7.0 × 1020 cm− 3 was obtained at a Ga2O3 content of 5 wt% in the target under room temperature deposition. With increasing deposition temperature, the lowest electrical resistivity of 3.8 × 10− 4 Ω cm was acquired at a deposition temperature of 200 °C. The values of plasmonic resonances wavelength could be changed from 1.35 to 2.39 μm by adjusting the carrier concentration. Material absorption losses in these GZO films are 10 times lower than that of conventional Ag films at telecommunication wavelengths. These results make GZO a promising low-loss plasmonic material operating at telecommunication wavelengths.