A Novel Near-field Photonic Thermal Diode with hBN and InSb

TL;DR

This paper proposes and theoretically demonstrates a new near-field photonic thermal diode using hBN and InSb, achieving high rectification ratios by exploiting temperature-dependent optical properties for contactless heat control.

Contribution

The work introduces a novel design for a photonic thermal diode based on hBN and InSb, utilizing their temperature-dependent optical properties for efficient heat rectification.

Findings

Rectification ratio exceeds 17 at 300 K with a 10 nm gap.

Rectification ratio exceeds 35 at higher temperatures and larger temperature differences.

The mechanism enables contactless control of radiative heat transfer.

Abstract

Similar to the diode in electronics, a thermal diode is a two-terminal device that allows heat to transfer easier in one direction (forward bias) than in the opposite direction (reverse bias). Unlike conductive and convective thermal diodes, a photonic thermal diode operates in a contactless mode and may afford a large operating temperature range. In this work, a novel near-field photonic thermal diode with hexagonal boron nitride (hBN) and indium antimonide (InSb) is proposed and theoretically demonstrated. The temperature dependence of the interband absorption of InSb is used to couple (or decouple) with the hyperbolic phonon polaritons in hBN. The numerical analysis predicts a rectification ratio greater than 17 for a 10 nm vacuum gap when operating at an average temperature of 300 K and a temperature difference of 200 K. The calculated rectification ratio exceeds 35 with higher average temperatures and larger temperature differences. The mechanism proposed here for achieving photonic thermal rectification provides a new way of controlling radiative heat transfer.