Effects of Interfacial Layer on the Enhancement Factor of Spheroidal Metal/Dielectric Nanocomposites in Passive and Active Host Matrix

Abstract

We investigated the effects of depolarization factor (L) and metal fraction (p) on the local field enhancement factor (LFEF) of spheroidal metal/dielectric nanocomposites (NCs) with passive and active host matrix. The expressions of the electric potentials are obtained by solving Laplace’s equations in the quasistatic limit for spheroidal metal/dielectric NCs. The equation of LFEF in the host of spheroidal metal/dielectric NCs was then constructed by incorporating L and the Drude-Sommerfeld model into these formulas. The results show that, regardless of how each parameter changes or remains constant, the LFEF of the NCs has a single set of peaks in both the passive and active host matrix. The parameter L affects the LFEF curves, and the output peaks in both host media exhibit shifted symmetrical patterns. On the other hand, the media with interfacial layer (I) were significantly impacted when a field was applied to the metal/dielectric NCs medium, and the LFEF increased successively in the given frequency range with a single peak. Furthermore, in passive and active dielectric host media, the LFEF of the spheroidal shell of the NCs increased progressively with thickness. The LFEF peaks are significantly impacted by radius that was studied in both passive and active host media. We investigated that when p increases, the peak values of the LFEF in the shell structure rise. Additionally, by altering each parameter, it was possible to create an adjustable LFEF that could be utilized for optical detection, nonlinear optics, and optical sensing applications.