Comparative study of the dopants (Mn vs. V) influence on the properties of sol-gel ZnO films

In the present work ZnO thin films doped with Mn and V in the same amount (2 at.%) were obtained by 5 successive depositions on Pt/Ti/SiO 2 /Si substrates using the sol–gel and spin coating method. Their structural, morphological, chemical, optical, and piezoelectric properties were investigated by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-Ray Photoelectron Spectroscopy (XPS), Spectroscopic Ellipsometry (SE) and piezoelectric characterizations. The work discusses the recent results regarding the comparative influence of Mn and V on the properties of the ZnO thin films, in view of various possible applications. For example, both types of films can be used as piezoelectric materials, but the samples containing V present higher piezoelectric coefficient than the films with Mn, having larger thickness and switchable spontaneous polarization induced by V dopants, thus an increased piezoelectric coefficient. The V-doped ZnO films are also more sensitive as gas detectors, than undoped ones, due to their increased porosity. Comparative influence of Mn and V dopants on the morphological, chemical, optical and piezoelectric properties of sol-gel ZnO films deposited on Pt/Ti/SiO 2 /Si substrate