Modulation of interface modes for resonance-induced enhancement of the interfacial thermal conductance in pillar-based Si/Ge nanowires

Abstract

The interfacial thermal conductance (ITC) plays a crucial role in nanoscale heat transfer, and its enhancement is of great interest for various applications. In this study, we explore the influence of resonance on the interfacial modes in pillar-based Si/Ge nanowires through nonequilibrium molecular dynamics simulations, employing both empirical and machine-learning potentials. Our results reveal a significant enhancement in the ITC by introducing pillars in the nanowire structure. The resonance-induced enhancement of the matching degree of the phonon density of states together with the calculation results of the phonon transmission coefficient indicate a significant improvement in both elastic and inelastic phonon transport at the interface. Moreover, we demonstrate the effective utilization of resonance to modulate the interfacial modes in pillar-based Si/Ge nanowires, resulting in improved phonon transport efficiency. This modulation is achieved by strategically repositioning the Si and Ge walls near the interface, leading to the development of the ATI-wall structure. Remarkably, the ATI-wall structure exhibits an unprecedented increase in the ITC compared to the original pillar-based design. To provide additional support for our conclusion, we conduct supplementary simulations using graphics processing unit molecular dynamics in conjunction with the neuroevolution potential to calculate the ITC. Our findings highlight the significance of interfacial mode modulation in enhancing the heat transfer in nanoscale systems and provide valuable insights for the design and optimization of thermal management devices and materials.