Temperature of a nanoparticle above a substrate under radiative heating and cooling

TL;DR

This paper models the temperature of a nanoparticle above a substrate under radiative heating and cooling, considering various parameters to aid in the thermal design of nanoscale systems.

Contribution

It introduces a new effective dipole-polarizability model to predict nanoparticle temperature under radiative conditions, accounting for multiple influencing factors.

Findings

Temperature depends on gap distance, wavelength, and polarization.

Material resonances significantly affect nanoparticle heating.

The model aids in designing nanoscale thermal systems.

Abstract

Controlling the temperature in architectures involving nanoparticles and substrates is a key issue for applications involving micro and nanoscale heat transfer. We study the thermal behavior of a single nanoparticle interacting with a flat substrate under external monochromatic illumination, and with thermal radiation as the unique heat loss channel. We develop a model to compute the temperature of the nanoparticle, based on an effective dipole-polarizability approach. Using numerical simulations, we thoroughly investigate the impacts of various parameters affecting the nanoparticle temperature, such as the nanoparticle-to-substrate gap distance, the incident light wavelength and polarization, or the material resonances. This study provides a tool for the thermal characterization and design of micro or nanoscale systems coupling substrates with nanoparticles or optical antennas.