Open AccessEnhancing thermal radiation by graphene-assisted hBN/SiO2 hybrid structures at the nanoscale
Author(s) -
Kezhang Shi,
Ran Liao,
Guanjun Cao,
Fanglin Bao,
Sailing He
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.00a591
Subject(s) - graphene , materials science , polariton , phonon , heat flux , graphene nanoribbons , black body radiation , plasmon , optoelectronics , surface plasmon , optics , photon , nanotechnology , condensed matter physics , radiation , heat transfer , physics , thermodynamics
A graphene-assisted hBN/SiO 2 hybrid structure is proposed and demonstrated to enhance near-field thermal radiation (NFTR). Due to the complementarity between the hyperbolic phonon polaritons of hBN and the surface phonon polaritons of SiO 2 at mid-infrared frequencies, coupling modes can remarkably improve the photon tunneling probability over a broad frequency band, especially when assisted by the surface plasmon polaritons of graphene sheets. Thus, the heat flux can exceed the blackbody limit by 4 orders of magnitude at a separation distance of 10 nm and reach 97% of the infinite limit of graphene-hBN multilayers using only two layers with a thickness of 20 nm each. The first graphene layer controls most of the heat flux, while the other layers can be used to regulate and optimize. The dynamic relationship between the chemical potential μ and the gap distance d are thoroughly discussed. Optimal heat flux of our graphene-assisted hBN/SiO 2 hybrid structure with proper choices of (μ 1 , μ 2 , μ 3 ) for different d (from 10 nm to 1000 nm) is further increased by 28.2% on average in comparison with the existing graphene-hBN triple-layer structure.