Near-field thermal rectification via an InSb/graphene/3C–SiC-nanowire heterostructure

Abstract

Thermal rectifiers allow asymmetric heat flux when the temperature bias between two terminals is reversed. Based on the near-field radiative heat transfer, the performance of thermal rectifiers can be significantly enhanced. Here, we propose a near-field thermal rectifier based on the InSb/graphene/3C–SiC-nanowire heterostructure. The rectifier consists of two terminals, one terminal is an InSb slab with a graphene-coated bottom, and the other terminal is a 3C–SiC nanowire array with a graphene cover on its top. By using fluctuational electrodynamics, we calculate the radiation heat flux and the corresponding thermal rectification efficiency (TRE). The results show that the strong asymmetric surface plasmon polaritons (SPPs) and hyperbolic phonon polaritons (HPPs) in the forward and reverse heat transfer scenarios guarantee a robust TRE. Besides, the TRE of the proposed heterostructure can be dynamically controlled and optimized via the chemical potential of graphene, the volumetric filling ratio of the nanowire array, and the terminal temperature. Specifically, the thermal rectification efficiency (1 – min (Qf, Qr)/max (Qf, Qr) with Qf and Qr denoting the forward and reverse heat flux, respectively) can exceed 80% at a wide-ranged terminal gap and reaches a maximum of 92.96%.