Enhanced interfacial thermal conductance across Si/defected SiC interface

Abstract

The effect of point defects (PDs) on interfacial thermal conductance (ITC) at the Si/3C–SiC interface is systematically investigated by nonequilibrium molecular dynamics simulations. Various PDs are introduced in the SiC interface region with atomic concentrations up to 5%. Our results show that carbon related vacancies significantly enhance ITC, with a linear increase observed as defect concentration rises. An amorphous SiC (a-SiC) interlayer is also modeled as a limiting case of defect-induced structural damage, resulting in a 35% increase in ITC compared to the pristine interface. Spectral decomposition and phonon-resolved analysis imply that defect-induced improvement in ITC takes place primarily due to low-frequency (below 10 THz) propagating phonons. The trade-off between improved heat transfer across the interface and reduced bulk thermal transport caused by defect-induced scattering is discussed. These findings provide valuable insight into phonon-mediated interfacial heat transport and demonstrate the potential of defect engineering strategies to improve interfacial thermal management in advanced SiC-based energy systems.