Transparent and Conducting Oxide Films: SiO₂-Doped ZnO

(SiO₂)(ZnO)_100- films with x = 2, 3, 4, and 5 wt.% were deposited on slide glass substrates at room temperature by the conventional Rf magnetron sputtering method. Their resistivities were investigated as a function of SiO₂ content. The lowest resistivity of 4.5×10^-3 Ω.· cm was obtained for the (SiO₂)(ZnO)_100- film with x = 2 wt.%. This film showed an excellent average transmittance of 85% in the visible range with a wide band gap over 3.4 eV and a high refractive index of 2.1. In addition, the electrical conductivity of the films was improved by annealing at a temperature films decrease range from 100 °C to 400 °C in vacuum. The resistivities of (SiO₂)(ZnO)_100- with increasing annealing temperature. In particular, SZO film with x = 2 wt.% shows a minimum resistivity of ~10^-3 Ω.cm after the heat treatment for 30 min at 300 °C in vacuum. Thus, we suggest that (SiO₂)(ZnO)_100- films being sufficiently transparent and having a high conductivity, are suitable for application as transparent and conductive oxide films.