Uniaxial stress tuning of interfacial thermal conductance in cubic BAs/4H-SiC heterostructures

Abstract

Understanding interfacial thermal transport is essential for improving thermal management in high-speed power electronic devices, where the efficient removal of excess heat is a critical challenge. In this study, a machine learning interatomic potential with near first-principles accuracy was employed to investigate the interfacial thermal conductance (ITC) between [111]-oriented cubic boron arsenide (cBAs) and [0001]-oriented 4H silicon carbide (4H-SiC), as well as its dependence on uniaxial stress. Among all possible bonding configurations at the cBAs(111)/4H-SiC(0001) interface, the B-C bonded interface was identified as the most energetically favorable. Non-equilibrium molecular dynamics simulations revealed that, under ambient conditions (300 K and 0 GPa), the ITC of the B-C interface reaches 353 $\pm$ 6 MW m$^{-2}$ K$^{-1}$, and increases monotonically to 460 $\pm$ 3 MW m$^{-2}$ K$^{-1}$ under a uniaxial stress of 25 GPa perpendicular to the interface. For comparison, the As-C bonded interface exhibits a lower ITC, increasing from 233 $\pm$ 7 to 318 $\pm$ 6 MW m$^{-2}$ K$^{-1}$ over the same stress range. These results demonstrate that proper interfacial bonding and moderate uniaxial stress can significantly enhance thermal transport across the cBAs(111)/4H-SiC(0001) heterointerface, offering valuable insight for thermal design in next-generation power electronics.