Pulsed laser deposited transparent and conductive V-doped ZnO thin films

Abstract

ZnO and vanadium-doped ZnO (0.7–4.1 at.%) thin films were deposited onto corning glass substrates by the pulsed laser deposition technique using a KrF excimer laser (λ = 248 nm). The films were deposited at 500 °C under an oxygen pressure of 1 Pa with a laser fluence of 2 J/cm2. The structural, morphological, optical and electrical properties as a function of the dopant atomic concentration were investigated by means of X-ray diffraction, Scanning Electron Microscopy, spectrophotometry, conductivity and Hall measurements. All the doped and undoped films show a preferential orientation along the c-axis with a deterioration at higher doping levels (>4 at. %). Besides, as the doping amount increases the in-plane stress leads to an increase of the c-axis lattice parameter. The films are transparent within the wavelength range 400–1200 nm. The electrical resistivity of the films drops from 8.2 10−3 to 1.3 10−3 Ω cm with an increase in the dopant concentration up to 0.9 at. % and then rises as the dopant level is increased further.