Modification of Emission Properties of ZnO Layers due to Plasmonic Near-Field Coupling to Ag Nanoislands

Abstract

A simple fabrication method of silver (Ag) nanoislands on ZnO films is presented. Continuous wave and time-resolved photoluminescence and transmission are employed to investigate modifications of visible and UV emissions of ZnO brought about by coupling to localized surface plasmons residing on Ag nanoislands. The size of the nanoislands, determining their absorption and scattering efficiencies, is found to be an important factor governing plasmonic modification of optical response of ZnO films. The presence of the Ag nanoislands of appropriate dimensions causes a strong (threefold) increase in emission intensity and up to 1.5 times faster recombination. The experimental results are successfully described by model calculations within the Mie theory.

Surface plasmon inhibited photo-luminescence activation in CdSe/ZnS core–shell quantum dots

“…This is caused by a long exciton lifetime of QDs (typically tens of nanosecondssee figure 4), which leaves enough time for the quenching to take place. The observed PL quenching effect is attributed to additional non-radiative channel related to the coupling of the excited QDs to LSP confined in AuNRs [17,19,[50][51][52][53]. We also point out, that the excitation wavelength (450 nm) is far away from the plasmon resonance of AuNRs, and the SP resonance of AuNRs has been chosen so that the SP-QD emission spectral overlap is minor.…”

“…We also point out, that the excitation wavelength (450 nm) is far away from the plasmon resonance of AuNRs, and the SP resonance of AuNRs has been chosen so that the SP-QD emission spectral overlap is minor. We can therefore neglect the effect of plasmon-induced enhancement of emissive dipole strength of QDs (emission enhancement) and excitation enhancement [50,54], and consider only the quenching effect.…”

Nanoscale mapping of plasmon and exciton in ZnO tetrapods coupled with Au nanoparticles

“…This was demonstrated on Ag-ZnO coupled nanospheres 7 due to the strong Ag plasmon resonance at ∼3.3 eV. The modification of the electronic properties of nanostructured interfaces between Ag and ZnO has been attributed to an electromagnetic coupling between excitons and plasmons 8 . Even photoluminescence and Raman scattering are enhanced by the coupling, and it was demonstrated in thin Au NPs covering ZnO films 9 10 , while an enhancements of UV photo-detection 11 as well as of photovoltaics and photochemical reaction 12 13 were demonstrated in other Au-ZnO nanocomposites.…”

Bulk Polymerization Photo‐Initiator ZnO: Increasing of the Benzoyl Formic Acid Concentration and LED Illumination

“…Photo‐semiconductors are highly reactive in the range of the bandgap (around 360 nm for ZnO) and absorb nearly all light smaller than this wavelength. The photo‐semiconductor ZnO is, for example, known for its fluorescence, optical absorbance, photo‐catalytic properties, application in solar cells/optoelectronics, and even photo‐induced polymerization (bulk and solution) using continuous light sources (wavelengths) . The additional “migration” problematic of molecular initiators for volume polymerization is a possible health risk as described in detail in recent publications .…”