SCANNING ELECTRON MICROSCOPE AND X-RAY DIFFRACTION STUDIES ON THE LATTICE CONSTANT OF SPIN-COATED Zn1-xMgxO THIN FILMS OF SOL-GEL METHOD

ZnO and Zn1-xMgxO thin films were prepared on glass and silicon substrates by spin coating method using 2-methoxyethanol solution of zinc acetate dihydrate and magnesium acetate dihydrate stabilized by monoethanolamine. The effects of drying and annealing condition of structural and optical properties of the films were studied. It was found that the samples annealed at 650°C improves the crystallographic orientation of the ZnO films grown by the sol-gel process significantly. Two types of substrates were used to examine the substrate effects of the growth of Zn1-xMgxO thin films. In corning glass substrates, the lattice constant decreased by a little with increasing concentration of Mg, whereas in the case of silicon substrates, the lattice constant decreased rapidly with x when compared to the glass substrates. The optical band energy gaps of Zn1-xMgxO thin films were slightly increased with increasing concentration of Mg.