Colossal near-field radiative heat transfer mediated by graded hybridization effect

Here, we propose a graded hybridization strategy for the enhancement of radiative heat transfer, which is based on the heterostructure consisting of multilayer graded SiO₂ gratings and black phosphorus (BP). In the near-field region, this graded hybridization strategy exhibits an advantage in radiative heat transfer capabilities when compared with conventional multiple surface plasmon polaritons (SPPs). Additionally, the proposed strategy has been demonstrated to exhibit excellent tunability, with significant alterations in heat flux observed when the gradient direction is altered, reaching up to 30 % change. By comparing the effects of forward and backward orientations of the graded grating on radiative heat transfer, it is determined that the forward configuration supports surface plasmon-phonon polaritons (SPPPs) waveguide mode, while the backward configuration completely suppresses this mode in the multilayer heterostructure. This investigation establishes a novel platform for efficient manipulating radiative heat transfer through the introduction of graded hybridization structures, with potential applications in a variety of fields, including thermal measurements, thermal management, and next-generation energy devices.