Electrically tunable radiative cooling performance of a photonic structure with thermal infrared applications

TL;DR

This paper presents a graphene-based metamaterial absorber with tunable infrared absorption properties, demonstrating potential for radiative cooling and thermal management by adjusting graphene's chemical potential.

Contribution

It introduces a novel multi-band graphene metamaterial structure with electrically tunable IR absorption for thermal infrared applications.

Findings

Broadband perfect absorption from 940 nm to 1498 nm

Narrowband perfect absorption at 5800 nm

Net cooling power over 18 units at ambient temperature

Abstract

Thermal infrared (IR) radiation has attracted considerable attention due to its applications ranging from radiative cooling to thermal management. In this paper, we design a multi-band graphene-based metamaterial absorber compatible with infrared applications and radiative cooling performance. The proposed structure consists of the single-sized metal-insulator-metal (MIM) grating deposited on metal/insulator substrate and single-layer graphene. The system realizes a broadband perfect absorption ranging from 940 nm to 1498 nm and a narrowband perfect absorption at the resonance wavelength of 5800 nm. Meanwhile, the absorptivity of the structure is suppressed within the mid-wave infrared (MWIR) and long-wave infrared (LWIR) ranges. Furthermore, to demonstrate the tunability of the structure, an external voltage gate is applied to the single-layer graphene. It is shown that, by varying the chemical potential of graphene layer from 0 eV to 1 eV , the absorption resonances at the mid-infrared (MIR) range can shift toward the shorter wavelengths. It is also observed that the structure can possess an average net cooling power over 18 at the ambient temperature, when is varied from 0 eV to 1 eV. Finally, we investigate the overall performances of the structure as a function of temperature to realize thermal infrared applications.