Electrical and Optical Properties of ZAO Thin Films Prepared by Sol-Gel Dip-Coating Method

Firstly, undoped ZnO thin films were prepared on glass substrates by Sol-Gel dip-coating (by assembled diminutive dip-coating device),and radio-frequency magnetron sputtering respectively. X-ray diffraction(XRD). Scanning Electron Microscopy(SEM), Spectrophotometer, Surface profilometry were used to characterize their properties. The results indicated:on the glass substrates, at the same annealed temperature, the films prepared by radio-frequency magnetron sputtering had more excellent crystallization quality. Then, Al-doped (ZnO:Al(ZAO)) thin films were solely prepared on glass substrates by Sol-Gel dip-coating method(by assembled diminutive dip-coating device), Scanning Electron Microscopy (SEM), UV-Visible spectrophotometry (UV-Vis), digital four-point probe electrical resistance measurement were used to characterize their surface morphologies, transmission property, film thickness, resistance etc. The results indicated: The morphologies of ZAO thin films were more compact when the Al³⁺ dopant concentration was 1.0 at%; with increasing annealing temperature, the average grain size of the film increased, the resistance decreased. Under the Al³⁺ dopant concentration of 1.5 at%, annealing temperature of 550degC and annealing time of 2 h , the average transmissivity of the film exceeded 70% within the visible region and resistance was 5.9 times 10^-2 Omega cm.