Effects of thickness and substrate temperature on the electrical and optical properties of In 2 O 3 -ZnO films

Abstract

The influences of thickness (d) and substrate temperature (Ts) on electrical and optical properties of In 2 O 3 -ZnO (IZO) films are investigated. IZO films are deposited on quartz substrates by reactive direct current magnetron sputtering. The target is 80 wt.% In 2 O 3 and 20 wt.% ZnO mixtures. d of the films deposited at room temperature varied from 63 to 651 nm. Ts of the films with thickness of about 200 nm varied from room temperature to 400 °C. Transmittances of the films are measured by spectrophotometer. The electrical properties such as resistivity, carrier concentration and mobility are studied by van der Pauw method. Experimental results show that the resistivity (ρ) monotonously decreases from about 1.2 × 10 -3 to 5.0 × 10 -4 Ωcm when d increases from 63 to 300 nm. As d=160 nm, the average transmittance in visible spectral region has a maximum (87%). Additionally, the average transmittances in visible spectral region for all the films deposited at different T s are about 82%, but the transmittance in near infrared spectral region decreases with the increase of T s . When T s increases from 100 °C to 400 °C, ρ and mobility monotonously decrease, but carrier concentration increases.