# Plasmonically Enhanced Spectrally-Sensitive Coatings for Gradient Heat Flux Sensors

## TL;DR

This paper presents spectrally-sensitive coatings enhanced by plasmonic effects for improved gradient heat flux sensors, enabling tunable optical properties for solar and thermal applications.

## Contribution

It introduces a method to design and optimize plasmonic semiconductor-oxide microinclusions for spectral control in heat flux sensors.

## Key findings

- Achieved up to 78% near-IR solar reflectance.
- Demonstrated tunable surface plasmon resonances.
- Enabled blocking of specific wavelengths for thermal management.

## Abstract

The spectral response and directional scattering of semiconductor-oxide core-shell spherical microparticles embedded in an insulating medium at low volume fraction are computed using Mie Theory and Multiscale Modelling methods. The surface plasmon resonances of low-bandgap semiconductor microinclusions have excellent and tunable scattering properties. By adjusting the size, material, shell thickness, and dielectric environment of the particles, the energies of the localized surface resonances are tuned to match the discrete solar spectrum. Near-IR solar reflectance efficiency factors of up to 78% are observed. Further the transmittance of broadband or specific wavelengths could be blocked. These spectrally-sensitive coatings have application as a back-reflector for solar devices, high temperature thermal insulator, and optical filters in Gradient Heat Flux Sensors (GHFS) for fire safety applications.