STUDIES ON STRUCTURAL, SURFACE MORPHOLOGICAL, OPTICAL, LUMINESCENCE AND UV PHOTODETECTION PROPERTIES OF SOL–GEL Mg-DOPED ZnO THIN FILMS

Abstract

Undoped and magnesium-doped zinc oxide thin films were prepared by the sol–gel method. Results from X-ray diffraction indicated that the films exhibited a hexagonal wurtzite structure and were highly oriented along the [Formula: see text]-axis. The intensity of the (002) diffraction peak increased with increasing the Mg doping concentration. Also, Mg doping inhibited the growth of crystallite size which decreased from 46[Formula: see text]nm to 38[Formula: see text]nm with doping concentration. Morphological studies by atomic force microscopy (AFM) indicated the uniform thin film growth and the decreasing of grain size and surface roughness with Mg doping. Optical analysis showed that the average transmittance of all films was above 90% in the visible range and Mg doping has significantly enhanced the bandgap energy of ZnO. Two Raman modes assigned to [Formula: see text] and [Formula: see text] for the ZnO wurtzite structure were observed for all films. UV emission peak and three defect emission peaks in the visible region were observed by photoluminescence measurements at room temperature. The intensity ratio of UV emission to the visible emission increased with the Mg concentration. Photocurrent measurements revealed that all films presented the photoresponses with [Formula: see text]-type semiconducting behavior and their generated photocurrents were reduced by Mg doping. The prepared thin films of high quality with improved properties by Mg doping could be proposed to workers in the field of optoelectronic devices for using them as a strong candidate.

Doping of Mg on ZnO Nanorods Demonstrated Improved Photocatalytic Degradation and Antimicrobial Potential with Molecular Docking Analysis

“…PL analysis is a valuable tool to get better information regarding impurities, transitions and dopants by studying emission spectra. Quantum size effects affect the physical properties of semiconductor materials at nanoscale, like ZnO changed its optical behavior by increase in quantum confinement observed from PL [ 40 ]. PL spectra of various concentrations of Mg incorporated into ZnO were measured with excitation λ~325 nm at room temperature (Fig.…”

Solution-Processed Mg-Substituted ZnO Thin Films for Metal-Semiconductor-Metal Visible-Blind Photodetectors

“…The PL intensity ratio of UV peak to visible peak is related to the crystal quality of the oxide films. We found that the emission intensity ratio of the Mg 0.1 Zn 0.9 O thin film was higher than that of the pure ZnO thin film, which can be attributed to decrease the defect concentration fraction and improved crystal quality [26].…”

“…It is well known that the diffraction peak broadening of polycrystalline metal oxide thin films is associated not only with crystallite size reduction but also lattice strain induced in the thin films [24]. While the ionic radii of the dopant Mg 2+ (0.057 nm) is relatively smaller than that of the host Zn 2+ (0.060 nm), some Zn 2+ ions in the crystal lattice of the host oxide material were easily replaced by Mg 2+ ions (>30 at.%) without changing the crystal structure, proving the possibility of MgZnO solid solution formation [25,26]. The substitution of Mg 2+ ions for Zn 2+ ions slightly distorted the lattice of the ZnO crystal.…”

“…The PL intensity ratio of UV peak to visible peak is related to the crystal quality of the oxide films. We found that the emission intensity ratio of the Mg0.1Zn0.9O thin film was higher than that of the pure ZnO thin film, which can be attributed to decrease the defect concentration fraction and improved crystal quality [26]. The electrical properties, including the major carrier concentration and electrical resistivity, of the MgxZn1−xO thin films were examined by Hall effect measurement and are presented in Figure 7.…”

Influence of Cu‐Doping on Linear and Nonlinear Optical Properties of High‐Quality ZnO Thin Films Obtained by Spin‐Coating Technique

“…[9] Zou et al have also studied and improved the nonlinear optical properties of CoO. [10] For this reason, they have utilized different dopants, such as, Al, [11] Mg, [12] Ga, [13] Co, [14] Fe, [15] and Cu. [13,14] Among all dopants, copper is the most suitable dopant for improving optical properties and it is considered as fast diffusing atoms in the ZnO structure.…”