Study On The Performance Of The Near Field Radiative Heat Transfer And Thermal Rectification Between Doped Silicon And Vanadium Dioxide Plates

Any object in nature can conduct radiative heat transfer in the form of electromagnetic waves.When the distance between radiative heat transfer objects is close to or less than the characteristic wavelength of the thermal radiation determined by the Wien displacement law,due to the significant influence of the near-field effect,the near-field total radiative heat flux between the objects may be exceed several orders of magnitude that between blackbodies.Thermal rectification systems based on near-field radiative heat transfer can overcome the performance limitations of traditional thermal rectification systems,and have important applications in fields of science and technology such as energy conversion systems,thermal logic circuits,information processing and so on.Therefore,the question of how to effectively modulate the near-field radiative heat transfer and improve the performance of the near-field thermal rectification has attracted extensive attention from scholars at home and abroad.In this paper,based on the concept of electromagnetic waves,a mathematical model of near-field radiative heat transfer is constructed by stochastic Maxwell’s equations combined with fluctuational electrodynamics,and the related electric and magnetic fields are solved with the help of the dyadic Green’s function.Then,by introducing the Poynting vector and the fluctuation-dissipation theorem,the calculation formulas of near-field radiative heat flux between two parallel smooth plates and between plates covered with monolayer film are obtained.Then the near-field radiative heat transfer and thermal rectification factor between the doped silicon and vanadium dioxide（VO₂）plates have been calculated by above the mentioned theoretical formulas,and the effects of the doping concentration of silicon and the vacuum gap on the near-field radiative heat flux and thermal rectification factor are analyzed.The results show that the p-polarized surface plasmon polaritons（SPPs）can be effectively adjusted by the doping concentration.It is emphasized that due to the interaction between the p-polarized SPPs of doped silicon and the p-polarized surface phonon polaritons（SPh Ps）or p-polarized hyperbolic modes（HMs）of insulating VO₂,the near-field radiative heat flux between plates have been enhanced,and then strengthen the corresponding the performance of thermal rectification.Finally,on the basis of the structure of the above calculation,a monolayer graphene film is introduced.Finally,on the basis of the structure of the above calculation,a monolayer graphene film is introduced.By optimizing the combination of above the materials,the effects of the chemical potential of graphene,the doping concentration,and the vacuum gap on the near-field radiative heat flux and corresponding thermal rectification factor are comprehensively considered.The results reveal that due to the modification of the p-polarized surface modes of the hot-emitting and cold-receiving ends by graphene,the interaction between the p-polarized surface modes of the corresponding system or between the p-polarized surface modes and the p-polarized HMs of the insulating VO₂ is changed,which can effectively modulate the near-field radiative heat transfer and the corresponding thermal rectification performance.This work is of great significance to the near-field radiative thermal management and the application of thermal devices based on the near-field radiative heat transfer.