24
A. Hu et al.
Obviously, the imaginary part (Im[ε(ω)]) of the dielectric functions of the
nanostructure, represents the loss in the nanostructure, and contributes to the heat
generation.
Surrounding the metal nanostructures, organic or inorganic mediums serve as the
dielectrics which affect the field distributions of the surface plasmons and in turn
impact the light absorption and heat generation processes. The absorption of light
by the surrounding medium also contribute to the heat generations to some extent.
The total heat power p can be obtained from
p =
v
q(r)dV
(1.2.25)
where the integral runs over the metal nanostructure volume V.
Let us consider a silver/organic nanocomposite cluster (Fig. 1.19), which consists
of layered silver nanoplates with 3 nm-thick polyvinylpyrrolidone (PVP) shell capped
on each of the nanoplate. The surface plasmons is extremely localized within the
ultra-small volume between two silver nanoplates due to the strong plasmon coupling
effect [94], whereas very limited electric field distribute in silver [75]. The heat, on
the other hand, generates mainly in the silver reign due to the strong absorption in
metal. However, the heat generated in PVP is several orders of magnitude smaller
Fig. 1.19 Photothermal effect in a silver/polyvinylpyrrolidone (PVP) nanocluster, a diagram of the
setup and SEM images of silver nanoplates, b calculated heat generation as a function of wavelength,
electric field distributions with light wavelengths of c 525 nm and d 1025 nm, and heat distributions
at wavelengths of e 525 nm, f 875 nm and g 1025 nm, respectively (Reprinted with permission
from [95]. Copyright 2015 Royal Society of Chemistry)
A. Hu et al.
Obviously, the imaginary part (Im[ε(ω)]) of the dielectric functions of the
nanostructure, represents the loss in the nanostructure, and contributes to the heat
generation.
Surrounding the metal nanostructures, organic or inorganic mediums serve as the
dielectrics which affect the field distributions of the surface plasmons and in turn
impact the light absorption and heat generation processes. The absorption of light
by the surrounding medium also contribute to the heat generations to some extent.
The total heat power p can be obtained from
p =
v
q(r)dV
(1.2.25)
where the integral runs over the metal nanostructure volume V.
Let us consider a silver/organic nanocomposite cluster (Fig. 1.19), which consists
of layered silver nanoplates with 3 nm-thick polyvinylpyrrolidone (PVP) shell capped
on each of the nanoplate. The surface plasmons is extremely localized within the
ultra-small volume between two silver nanoplates due to the strong plasmon coupling
effect [94], whereas very limited electric field distribute in silver [75]. The heat, on
the other hand, generates mainly in the silver reign due to the strong absorption in
metal. However, the heat generated in PVP is several orders of magnitude smaller
Fig. 1.19 Photothermal effect in a silver/polyvinylpyrrolidone (PVP) nanocluster, a diagram of the
setup and SEM images of silver nanoplates, b calculated heat generation as a function of wavelength,
electric field distributions with light wavelengths of c 525 nm and d 1025 nm, and heat distributions
at wavelengths of e 525 nm, f 875 nm and g 1025 nm, respectively (Reprinted with permission
from [95]. Copyright 2015 Royal Society of Chemistry)