Transparent conductive ZnO thin films grown by chemical spray pyrolysis: the effect of Mg

Mg doped ZnO films have been prepared via Ultrasonic Spray Pyrolysis technique. Effect of Mg concentration on the structural, optical, surface and electrical properties of ZnO films have been investigated. X-ray diffraction studies showed that all of the samples are polycrystalline with hexagonal wurtzite structure. Thicknesses and optical constants (refractive index and extinction coefficient) have been determined using spectroscopic ellipsometry technique and Cauchy-Urbach model. UV-VIS spectroscopy has been used to take transmittance measurements and optical band gap values have been calculated using optical method. Surface morphologies and roughness values of the films have been investigated by atomic force microscopy. A four-probe setup has been used to determine the electrical resistivity values. Photoluminescence spectra showed an ultraviolet emission band around 365-400 nm and the visible emission peaks between 469 and 590 nm. It has been concluded that Mg doped ZnO films have value to work on and may be promising materials for optoelectronic applications.