Thin ZnO films produced by pulsed laser deposition

In this work, thin ZnO films have been produced by pulsed laser deposition on (001) SiO2 substrates. The influence of the substrate temperature and oxygen pressure applied on the structural, morphological, and optical properties of the films were investigated. All ZnO films are textured along (002) direction. The increase of the substrate temperature enhances the diffraction peak intensity for all oxygen pressures applied. Highest intensity peak for a fixed temperature was obtained at pressure in the range 0.05 - 0.1 mbar. The increase of the substrate temperature at 0.1 mbar leads to deposition of smoother films with an average RMS value of 9- 11 nm. The film morphology changes with the increase of oxygen pressure at fixed temperature. Highest optical transmission was achieved at room temperature. The increase of the oxygen pressure reduces the film transmission in the visible range of the spectra. The value of the measured waveguide losses strongly depends on the crystalline quality and surface roughness of the films. The optical losses decrease to a value lower than 3 dB/cm when temperature increases.