Calculation of the Localized Surface Plasmon Resonances of Au Nanoparticles Embedded in NiO

Abstract

The present article examined the influence of size and periodicity of simulated gold (Au) nanoparticles (NPs) embedded in Nickel Oxide (NiO) matrix on localized plasmonic resonances (LSPRs). The scope of this work is to comparatively study the theoretical outcomes exhibited against the experimental results delivered from previous works, including a significant number of simulations and testing of numerous NPs diameter values. A comparison between Au and NiO NPs over silver (Ag) and NiO NPs is also reported to investigate whether the nature of noble metal affects its behavior in terms of LSPRs. The computational results strongly support that the appearance and intensity of LSPRs is straightforward to the increase in the diameter of NPs. The simulation results are in a good agreement with the literature of small NPs, offering the opportunity to further understand the LSPR phenomenon and its more effective implementation to opto-electronic applications. Rigorous Coupled Wave Analysis (RCWA) is performed to stimulate the justification and knowledge of the theoretical conclusions.

ZnO Matrices as a Platform for Tunable Localized Surface Plasmon Resonances of Silver Nanoparticles

“…This may be interpreted by the fact that, before coating, the NPs were surrounded by air with a dielectric constant of 1. Similar results were observed with NiO as the capping layer [49][50][51]. Furthermore, the absorption curves of ZnO-covered NPs exhibited a higher initial absorbance compared to the uncovered NPs.…”

“…This red shift can be attributed to the large value of the refractive index (n~1.95) of ZnO. Similar results were observed when using NiO as the capping layer [49][50][51]. The ZnO capping layer also caused an increase in the full width at half-maximum (FWHM) for the main LSPR of Ag #2, while for the thicker Ag #3, a decrease in FWHM values for both LSPR peaks was observed.…”

“…The system under study is visually represented in Figure 7. NPs are represented as cubes and cylinders because they allow faster computational processing when applying the RCWA method [49,51,52]. NPs are positioned on a SiO2 substrate, surrounded by the ZnO matrix.…”

Silver Nanoparticles’ Localized Surface Plasmon Resonances Emerged in Polymeric Environments: Theory and Experiment

“…This could be attributed to the larger value of the dielectric constant of the polymeric coatings (~1.5) compared to that of air. This consistent red shift has also been observed in Au and Ag NPs in NiO [44,45] and ZnO [41] dielectric environments, due to their relatively large dielectric constants. Additionally, the same trend was also observed when investigating the impact of similar polymeric coatings on the plasmonic behavior of Au NPs [40].…”

“…For net silver NPs, the dielectric environment was substituted with air. Ag NPs are depicted as cylinders or cubes because it is proven that these geometrical shapes consume less computational time and resources once simulated when applying RCWA [44,45]. A periodic array is also performed in order to balance the presence of one individual NP, which is non-evaluated due to the observed proximity of Ag NPs fabricated in situ along with the observed disorder structure probed by AFM.…”