Spectroscopic ellipsometry study of the optoelectrical properties of In2O3:Sn–ZnO:Al thin films deposited through alternating sputtering

摘要

In this study, indium tin oxide (ITO) and indium zinc oxide (IZO) films were deposited on quartz glass through alternating sputtering. The optical and electrical properties of these films were characterized through spectroscopic ellipsometry (SE). The optical constants of ITO and IZO films were accurately estimated using a model that combined the Tauc–Lorentz, Gauss, and Drude models. However, the estimated resistivity was close to the Hall measurements only when the film thickness was higher than 250 nm. Anisotropy caused by the preferential orientation of crystallites increased the difficulty of the SE fitting process. Furthermore, a k -factor defined on the basis of the estimated optical constants was used to examine the Zn content of the IZO films. Variation in the k -factor was consistent with the band gap of the IZO films.