Thermal emission from three-dimensional arrays of gold nanoparticles

We study the blackbody spectrum from slabs of three-dimensional metallodielectric photonic crystals consisting of gold nanoparticles using an ab initio multiple-scattering method. The spectra are calculated for different photonic-crystal slab thicknesses, particle radii, and hosting materials. We find in particular that such crystals exhibit a broadband emission spectrum above a specific cutoff frequency with emissivity of about 90%. The studied photonic crystals can be used as efficient selective emitters and can therefore find application in thermophotovoltaics and sensing.

Figure 1

Transmittance, reflectance, and absorbance of light incident normally on a 128-layers thick slab of a fcc crystal consisting of gold spheres $(S=5\mathrm{nm})$ in air $({ϵ}_h=1)$, with $f=0.3$.

Figure 2

SH emissivity for different numbers of layers (slab thicknesses) of the photonic crystal described in Fig. 1.

Figure 3

SH emissivity of a 64-layer thick slab of an fcc crystal of gold spheres $(S=5\mathrm{nm})$ in air (${ϵ}_h=1$—solid line), silica (${ϵ}_h=1.88$—dashed line), and gelatine (${ϵ}_h=2.37$—dotted line), with $f=0.3$. We have assumed that the host medium surrounding the spheres also covers the whole space.

Figure 4

SH emissivity of a 64-layer thick slab of an fcc crystal of gold spheres $(S=5\mathrm{nm})$ in air, for different volume filling fractions $f$ (fixed lattice constant and different sphere radii).