Excitation of hybrid modes constituted by different material-supported polaritons is a common way to enhance the near-field radiative energy transport, which has fascinating promise in applications of thermal photonics. Here, we investigate near–field thermal radiation mechanisms in heterostructure composed of hBN film and black phosphorus single layer. The results show that this heterostructured system can give rise to a remarkable enhancement for photon tunneling, outperforming the near-field thermal radiation properties of its building blocks, as well as some other representative heterostructures. Moreover, we find that the anisotropic hybrid effect can induce a remarkable topological reconstitution of polaritons for hBN film and black phosphorus, forming a novel anisotropic hybrid polaritons. Notably, such hybrid modes show significant topological differences compared to hBN film and black phosphorus in the type-I Reststrahlen band due to the anisotropic anticrossing hybridization effect. Lastly, we systematically analyze the evolution of such hybrid polariton modes as a function of hBN film thickness and the corresponding influence on radiative properties of the heterostructure. This work may benefit the applications of near-field energy harvesting and radiative cooling based on hybrid polaritons in anisotropic two-dimensional material and hyperbolic film.

Light-assisted micronanoscale temperature control in a complex nanoparticle network has attracted a lot of research interest. Many efforts have been put into the optical properties of nanoparticle networks, and only a few investigations have reported its light-induced thermal behavior. We consider a two-dimensional (2D) square-lattice nanoparticle ensemble made of typical metal Ag with a radius of 5 nm. The effect of complex multiple scattering and thermal accumulation on light-induced thermal behavior in plasmonic resonance frequency (around 383 nm) is analyzed through the Green's function approach. The regime borders of both multiple scattering and thermal accumulation effects on the photothermal behavior of the 2D square-lattice nanoparticle ensemble are figured out clearly and quantitatively. The dimensionless parameter φ is defined as the ratio of a full temperature increase to that without considering the multiple scattering or thermal accumulation to quantify the multiple scattering and thermal accumulation effects on photothermal behavior. The more compact the nanoparticle ensemble is, the stronger the multiple scattering effect on thermal behavior is. When the lattice spacing increases to dozens times of the radius, the multiple scattering becomes insignificant. When φ≈1 (lattice spacing increases to hundreds times of the radius), the thermal accumulation effects are weak and can be neglected safely. The polarization-dependent distribution of the temperature increase of nanoparticles is observed only in the compact nanoparticle ensemble, while for a dilute ensemble, such a polarization-dependent temperature increase distribution can no longer be observed. This work may help with the understanding of the light-induced thermal transport in the 2D particle ensemble.

The presence of interlayer interactions in twisted bilayer graphene(TBG) enhances several characteristics, including the optical and electronic properties. We theoretically investigate the magic angle of TBG according to the vanishing of Fermi velocity and find double magic angles in a series. Thermal radiation from TBG can be tuned to the far infrared range by changing twist angles. The peculiar radiation spectrum is out of atmospheric window, which can be of great use in invisibility and keeping warm. The total radiation of TBG is slightly more than twice of a single layer graphene.