Radiative thermal switch via metamaterials made of vanadium dioxide-coated nanoparticles

TL;DR

This paper introduces a novel radiative thermal switch using VO2-coated nanoparticles in metamaterials, achieving over twice the switching ratio of traditional designs, enabling advanced control of near-field heat transfer.

Contribution

It presents a new metamaterial-based thermal switch with VO2-coated nanoparticles that significantly enhances switching performance compared to conventional VO2 slabs.

Findings

Switching ratio exceeds 90% at 100 nm gap

Enhanced heat transfer control via VO2 shell coupling

Potential for thermal logic circuit applications

Abstract

In this work, a thermal switch is proposed based on the phase-change material vanadium dioxide (VO2) within the framework of near-field radiative heat transfer (NFRHT). The radiative thermal switch consists of two metamaterials filled with core-shell nanoparticles, with the shell made of VO2. Compared to traditional VO2 slabs, the proposed switch exhibits a more than 2-times increase in the switching ratio, reaching as high as 90.29% with a 100 nm vacuum gap. The improved switching effect is attributed to the capability of the VO2 shell to couple with the core, greatly enhancing heat transfer with the insulating VO2, while blocking the motivation of the core in the metallic state of VO2. As a result, this efficiently enlarges the difference in photonic characteristics between the insulating and metallic states of the structure, thereby improving the ability to rectify the NFRHT. The proposed switch opens pathways for active control of NFRHT and holds practical significance for developing thermal photon-based logic circuits.