Structural, Optical and Electrical Properties of ZnO Sprayed Thin Films Doped with Fluorine

Abstract

F-doped ZnO films (FZO) of about 400 nm thicknesses were prepared on glass substrates by the chemical spray pyrolysis technique. X-ray diffraction patterns showed that the undoped and F-doped ZnO films exhibit the hexagonal wurtzite crystal structure with a preferential orientation along [002] direction. No secondary phase is observed in F-doped ZnO films. All films exhibit a transmittance around 80% in the visible range. Photoluminescence spectra at room temperature of undoped and F doped ZnO thin films are presented. The wide PL bands centered at 510 and 680 nm are characteristic of deep levels of oxygen vacancies in the ZnO matrix, and zinc interstitial position. The FZO films are degenerate and exhibit n-type electrical conductivity. The lowest electrical resistivity was 7.6 10−3 Ω cm.