Abstract:
Nanoparticle is a general term in which nano refers to size and denotes a billionth of
a unit. Since nanoparticles have been in use, they have become the cornerstones of
nanoscience and nanotechnology. Their applications in the real world require spe
cific sizes, shapes, compositions, and structures. Hence, this dissertation is devoted
to the theoretical and numerical investigations of the effects of size, shape, surface
plasmons, and host medium ontheoptical properties of core-shell nanocomposites
(NCs). We reviewed on the size-dependent local field enhancement factor (LFEF) of
CdSe@ZnSe@Ag core/spacer/shell spherical nanoparticles within the framework of
quasi-static approximation was numerically and theoretically investigated. From the
potential distributions in the core, shell(s), and host medium, and using the modi
f
ied Drude-Sommerfeld model, we separately obtained the expressions for LFEF of
core/spacer/shell nanocomposites. By changing the sizes of each of the compo
nents of the nanocomposites in these expressions, we understand that the LFEF of
CdSe@ZnSe@Ag increases with a decrease in the size of the core. At the same time,
theresonancepeaksareredshiftedintheinnerinterfaceandblueshiftedintheouter
interface of the shell. The result also reveals that whether the shell radius is kept con
stant or decreased, increasing the core size produces a lower field enhancement fac
tor showingthatthecoresizeisacrucialparametertochangethefieldenhancement
factor of the dielectric core and metal shell nanoparticle (NP). In general the sizes of
the core, the spacer and the shell have vigorous effects on the local field enhance
ment factor of core-shell nanoparticles. The feature direction of this study likely in
volves experimental characterization and theoretical modeling to explore how the
size variations of CdSe@ZnSe@Ag core triple-layer spherical nanoparticles influence
their local fieldenhancementfactor,whichiscrucialimportancefortheirapplication
in nanotechnology and photonics.
