Effects of substrate temperature on crystalline structure, electrical and optical properties of F-doped ZnO thin films deposited by magnetron sputtering

Abstract

Highly transparent and conductive F-doped ZnO (FZO) thin films were deposited on glass substrates by magnetron sputtering from ZnF2 -doped ZnO ceramic target. Crystalline structure, electrical and optical properties of the films were studied under the change of substrate temperature (100-300o C). The effects of substrate temperature on the films were investigated by X-ray diffraction (XRD), Hall effect-based measurement and UV-Vis spectroscopy. The XRD results suggested that the FZO films had the characteristic hexagonalwurtzite structure of ZnO with c-axis preferential orientation perpendicular to the substrate. In respect of electrical property, electron mobility of the films increased monotonically by increasing the substrate temperature due to the improved crystallinity, while the carrier concentration reached peak at 200o C. The average transmittance of all the FZO films was more than 83% in the broad wavelength region (400-1000 nm). The blue-shift of absorption edge and widened optical band gap were in agreement with the BursteinMoss effect.