Manipulation of Abnormal Thermal Conductance at the Graphene/SiC Interface through Topological Defects

Low interfacial thermal conductance often emerges as a primary barrier to effective heat management in advanced nanodevices. This study examines how topological defects affect the interfacial thermal conductance of graphene/SiC lateral heterostructure, utilizing nonequilibrium molecular dynamics simulations. The significant lattice mismatch between graphene and SiC results in a pristine interface that experiences severe strain and structural distortion, ultimately reducing the level of phonon transmission. By introduction of 5|8|5 topological defects, the interfacial deformation is effectively alleviated, thereby improving phonon coupling across the boundary. The results reveal an unconventional increase in interfacial thermal conductance, with the maximal value achieved when three defects are incorporated, representing a 61% improvement compared with the pristine interface. However, an excessive number of defects can lead to a reduction in the thermal conductivity. These findings demonstrate that controlled defect engineering offers a tunable pathway to optimize interfacial heat transport in 2D heterostructures, providing valuable insights for thermal management in nanoscale devices.