Effect of Ag doping on the microstructure and photoluminescence of ZnO nanostructures

Abstract

ZnO nanostructures were obtained by metal-organic chemical vapour deposition via Ag catalyst assisted growth in a temperature range of 200 -500 °C. Growth at temperatures above 500 °C resulted in vertically aligned ZnO nanorods. Ag incorporation into ZnO up to 0.4 at. % promoted creation of basal plane stacking fault (BSF) defects and corrugation of the side facets of the nanorods. The presence of BSFs give rise to an additional photoluminescence peak with a wavelength of ~386 nm, which is slightly red-shifted compared to the commonly observed NBE emission at ~375 nm. The observed emission was found to be specifically observed from the side facets of the nanorods. It is suggested that this emission is due to a high concentration of BSFs in the ZnO as a result of an incorporation of Ag as acceptor dopant.SEM image of an Ag-doped ZnO nanorod with corrugated side facets. The observed corrugation is accompanied by a high concentration of basal plane stacking faults.

Effect of Ag clusters doping on the photoluminescence, photocatalysis and magnetic properties of ZnO nanorods prepared by facile microwave-assisted hydrothermal synthesis

“…The Ag Zn energy formation is known to be smaller than the one for Ag I . Therefore, Ag uses to substitute Zn, moving the ZnO gap toward reduced energy levels and placing it as an excellent candidate for a p-type semiconductor [39]. In other words, the technique confirms the obtainment of ZnO and the partial substitution by Ag in its structure.…”

“…This is due to the low working temperature applied with the employed method, which results in the formation of extremely small crystallites (or particles) [38]. Here, when the particles are present in single crystals, the term crystallite can be used with the same meaning [39].…”

Transition-Metal-Doping of CaO as Catalyst for the OCM Reaction, a Reality Check

“…With highly coordinated sites, such as terrace sites being considered inactive in the OCM reaction, the increase of the lower coordinated sites explains the observed higher activity of the Mn-doped CaO. It is also quite reasonable that this effect is limited since highly isolated foreign ions can have a large impact on the surface structure by introducing lattice distortions, strain, stress (Khranovskyy et al, 2014), when the foreign atoms are getting close to each other, shown by the signal broadening in the EPR spectra (Figure 6B), the effect might be canceled out. Seeing a similar behavior with the Ni and Mn series also supports this hypothesis.…”

Cap‐Like Ellipsoid Deposition on the ZnO Nanowires for Large Increase of Fluorescence Induced by Localized Field Enhancement Effect

“…[ 11 ] Interestingly, 1D ZnO nanostructures including nanorods (NRs), [ 12 ] nanowires (NWs), [ 13 ] nanorings, [ 14 ] and other morphologies [ 15 ] have advantages as fluorescence materials from properties such as a high aspect ratio, good chemical stability, wide bandgap, and high exciton binding energy. Researchers have improved the synthesis methods to obtain high‐quality ZnO nanostructures by altering surface morphology, [ 16 ] defect diffusion mechanism, and doping metal elements, [ 17 ] and then regulating the bandwidth and carrier concentration to obtain outstanding fluorescence properties. [ 18 ]…”

“…[11] Interestingly, 1D ZnO nanostructures including nanorods (NRs), [12] nanowires (NWs), [13] nanorings, [14] and other morphologies [15] have advantages as fluorescence materials from properties such as a high aspect ratio, good chemical stability, wide bandgap, and high exciton binding energy. Researchers have improved the synthesis methods to obtain high-quality ZnO nanostructures by altering surface morphology, [16] defect diffusion mechanism, and doping metal elements, [17] and then regulating the bandwidth and carrier concentration to obtain outstanding fluorescence properties. [18] In addition, employing the strong coupling between local surface plasmon resonance and intrinsic exciton radiative recombination, some researchers propose an experimental heterojunction scheme to promote fluorescence properties by coating noble metal or other semiconductor material on the top of ZnO nanostructures.…”