Effect of interparticle plasmon coupling and temperature on the optical properties of bimetallic composite nanoparticles with a core-shell structure

Abstract

In this work, the optical properties of bimetal composite nanoparticles with a core-shell structure are investigated in the framework of quasi-static and Maxwell-Garnett approximation. The influence of interparticle plasmon coupling and temperature on the optical absorption of bimetallic core-shell nanoparticles is studied while the shell consists of Al and Cu particles. In fact, dependence of the optical absorption and its full width at half maximum on the dielectric constant of the core, host matrix, and embedding medium for both spherical and cylindrical bimetallic nanocomposites is shown. It was found that both the plasmonic shifting and bandwidth are dependent on the volume fraction of metal nanoparticles (filling factors) and the temperature. However, a new plasmon oscillation mode is created and observed in the spectra owing to the interparticle plasmon coupling of different metallic particles which cannot be found in a monometal nanocomposite.

The Optical Properties of Nano-Materials and Electromagnetic Wave Propagation Visualized with MATLAB

“…Optical properties of nobel metal nano-structures have received great attentions due to their plasmonic properties, especially the optical absorption effects induced by localized surface plasmon resonance (LSPR) have attracted much attention in recent years [6,7]. The electrical field scattering problems could be solved with Laplace's equation for the potential [8,9], which is very similar to the solution of media sphere. The radius of dielectric-metal core-shell multi-layered nanosphere is 25nm in this study, which is smaller than the incident wavelength.…”

“…These three absorption peaks could be explained by the plasmon hybridization theory [7,11], dielectric-metal core-shell multi-layered nanosphere could be considered as a solid silver core inserted into a dielectric-silver nano-shell. LSPR can be considered as an interaction between the plasmon responses of a silver core with its energy mode 〉 | plasmon mode, the distribution of induced charges on the surface of silver core is oppositely aligned with plasmon of nano-shell, which reduces the dipole moment, so the absorption peak is too weak to be observed in experiments [8,9,11]. In order to make the plasmon modes of dielectric-metal core-shell multi-layered nanosphere understand fully, the distribution of local electrical field intensity at…”

Geometrical Tunability and Local Electric Field Distribution of Gold-dielectric-silver three-layered Cylindrical Nanotube

“…Zhu et al have reported the local dielectric environment dependent local field enhancement properties in double concentric silver nanotube using plasmon hybridization method and quasi-static calculation [20]. Daneshfar et al have studied optical and spectral tunability of multilayer spherical and cylindrical nanoshell with quasi-static theory [21]. Wu have studied the the refractive sensitivity of silver-dielectric-silver and gold-dielectricgold nanotube, and the result shows that the sensing ability can be improved by reducing the thickness of the inner gold shell or increasing the thickness of the outer gold shell [22,23].…”

Optical absorption tunability and local electric field distribution of gold-dielectric-silver three-layered cylindrical nanotube*

“…[20] Daneshfar et al have studied optical and spectral tunability of multilayer spherical and cylindrical nanoshell with quasi-static theory. [21] Wu et al have studied the multiple Fano resonance of nanrod and nanoring, which has been applied in refractive index sensing and high-sensitivity biosensors. [22] The optical absorption of three-layered nanoshell shows that the LSPR can be well adjusted the parameters of nanoshell.…”