Morphologic and optical characterization of ZnO:Co thin films grown by PLD

Abstract

The morphological properties of the surface and optical characteristics of nanocomposite ZnO:Co structures grown on substrates of monocrystalline silicon and sapphire by pulsed laser deposition (PLD) method have been studied. The influence of thermal annealing on formation of characteristically developed surface of films has been analyzed. The experimental transmission and reflectance spectra in the visible region have been measured. In the framework of the dielectric function, the optical constants n and k and dispersion parameters of oscillators that provide the best fit with experimental data have been obtained. From the infrared reflectance spectra of ZnO:Co structures, the frequency positions of Е₁(LO) and Е₁(ТО) optical phonons have been determined. It gives a possibility to suppose that the obtained films possess the wurtzite structure.