Amplification and modulation effect of elliptical surface polaritons on a thermal diode

Abstract

With the development of surface polaritons of two-dimensional metasurfaces with high mode density, considerable attention has been paid to their application in optimising the performance of the thermal diode; however, presently, the main focus is on isotropic metasurfaces. In this study, we investigated the amplification and modulation effect of elliptical surface polaritons on a near-field radiative thermal diode. Introducing black phosphorus (BP) in forward and reverse terminals of the thermal diode (comprising VO2 and Si) demonstrated prominent amplification of rectification performance (of ∼3.59 times) in the modified thermal diode than in the one without BP. Selecting different electron densities of BP and different doping densities of Si revealed the influence of the hybridisation effect of elliptical polaritons on thermal rectification and near-field radiative heat transfer. Finally, based on the in-plane intrinsic anisotropic lattice of BP, the modified thermal diode facilitated highly flexible manipulation of rectification performance through mechanical rotating, which to the best of our knowledge, has never been discussed in the field of near-field radiative diodes. Our findings provides significant insights to intensify asymmetric energy transfer and explore the radiative heat transfer mechanism of a coupled system comprising an anisotropic metasurface and an out-plane anisotropic material.