Abstract
The rare earth element, i.e., praseodymium (Pr) co-doped aluminium zinc oxide (AZO) thin films is coated on a well-cleaned glass substrate by facile and cost-effective nebulizer spray technique. The Pr co-doping concentrations varied from 0 to 1.5% with the AZO structure in the steps of 0.5%. The structural analysis was characterized by X-ray diffraction (XRD), showing that all the diffracted peaks exhibit polycrystalline hexagonal wurtzite structure and the size of the crystallites is abridged with increasing Pr doping level due to lattice defects. In Raman analysis, the existence of high mode peak E-2 at 437 cm(-1); confirmed ZnO wurtzite structure. From the morphological study, it is clearly visualized that the film possesses spherical shaped grains which were uniformly distributed without any pinholes and voids. The surface roughness of the films was increased considerably from 22 to 39 nm on growing Pr doping from 0 to 1.5% as seen using atomic force microscope. Energy dispersive X-ray analysis and elemental mapping images clearly showed the subsistence of Al, Zn, O and Pr elements in Pr:AZO film. The prepared films exposed good transmittance range between 84 and 90% and the optical band gap was found to be 3.28 eV for initial Pr (0.5%) doping concentration. The PL spectra clearly showed that a high intense emission peak observed at 390 nm are associated with NBE which indicates that the film has good optical quality. Hall measurement revealed that the prepared film, i.e., 1.5% Pr-doped AZO film has low resistivity and high carrier concentration which is perfectly suit for optoelectronic device applications.