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

• Published in: Journal of sol-gel science and technology Vol. 104; no. 1; pp. 67 - 77
• Main Authors: Zaharescu, Maria, Anastasescu, Mihai, Stroescu, Hermine, Calderon-Moreno, Jose M., Apostol, Nicoleta, Preda, Silviu, Vladut, Cristina Maria, Mihaiu, Susana, Petrik, Peter, Gartner, Mariuca
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-10-2022; Springer Nature B.V
• Subjects: Ceramics; Chemistry and Materials Science; Comparative studies; Composites; Dopants; Gas detectors; Glass; Inorganic Chemistry; Materials Science; Microscopy; Nanotechnology; Natural Materials; Optical and Electronic Materials; Optical properties; Original Paper: Characterization methods of sol-gel and hybrid materials; Photoelectrons; Piezoelectricity; Porosity; Silicon dioxide; Silicon substrates; Sol-gel processes; Spectroellipsometry; Spin coating; Thin films; X ray photoelectron spectroscopy; Zinc oxide; ZnO thin films; Piezoelectric properties; Microstructure; Sol-gel method; Surface chemistry; Mn and V doping
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-022-05909-7

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
Highlights
V and Mn are substituting for Zn in the ZnO host lattice.
The increased porosity of V-doped ZnO comparative with Mn-doped sample is a desired property in gas detection applications.
V
4+
/V
3+
ratio is higher than Mn
4+
/Mn
2+
ratio, influencing positive piezoelectric response.
Higher porosity and an increased piezoelectric response were obtained for V-doped ZnO sample.