Preparation and properties of Mg0.2Zn0.8O:Al UV transparent conducting thin films deposited by RF magnetron sputtering at room temperature with rapid annealing

Abstract

Mg0.2Zn0.8O:Al UV transparent conducting thin films were deposited by RF magnetron sputtering at room temperature with a rapid annealing process. Effects of sputtering power, argon gas pressure and annealing temperature on structure, optical and electrical properties of Mg0.2Zn0.8O:Al films were investigated. The experimental results show that Mg0.2Zn0.8O:Al thin films exhibit high preferred c-axis-orientation. The sputtering power, argon gas pressure and annealing temperature all exert a strong influence on the electrical resistivity of Mg0.2Zn0.8O:Al thin films due to the variation of carrier concentration and mobility in films derived from the change of effective doping and crystallinity. The lowest electrical resistivity of Mg0.2Zn0.8O:Al thin films is 3.5 × 10−3 Ω·cm when the sputtering power is 200 W, the argon gas pressure is 2.0 Pa and the annealing temperature is above 500 °C. The transparent spectrum range of Mg0.2Zn0.8O:Al thin films extend to ultraviolet band and the optical transmittance is between 80 and 90%, but the sputtering power, argon gas pressure and annealing temperature all exert little influence on optical transmittance.