  Directing the propagation of near-infrared radiation is a major concern in
improving the efficiency of solar cells and thermal insulators. A facile
approach to scatter light in the near-infrared region without excessive heating
is to embed compact layers with semiconductor particles. The directional
scattering by semiconductor@oxide (core@shell) spherical particles (containing
Si, InP, TiO$_2$, SiO$_2$, or ZrO$_2$) with a total radius varying from 0.1 to
4.0 {\mu}m and in an insulating medium at low volume fraction is investigated
using Lorenz-Mie theory and multiscale modelling. The optical response of each
layers is calculated under irradiation by the sun or a blackbody emitter at
1180 K. Reflectance efficiency factors of up to 83.7% and 63.9% are achieved
for near-infrared solar and blackbody radiation in 200 {\mu}m thick compact
layers with only 1% volume fraction of bare Si particles with a radius of 0.23
{\mu}m and 0.50 {\mu}m, respectively. The maximum solar and blackbody
efficiency factors of layers containing InP particles was slightly less (80.2%
and 60.7% for bare particles with a radius of 0.25 {\mu}m and 0.60 {\mu}m,
respectively). The addition of an oxide coating modifies the surrounding
dielectric environment, which improves the solar reflectance efficiency factor
to over 90% provided it matches the scattering mode energies with the incident
spectral density. The layers are spectrally-sensitive and can be applied as a
back or front reflector for solar devices, high temperature thermal insulators,
and optical filters in Gradient Heat Flux Sensors for fire safety applications.
