Thermal Transport Study in a Strained Carbon Nanotube and Graphene Junction Using Phonon Wavepacket Analysis

This study investigates single-mode phonon scattering from a junction structure consisting of a (6,6) single-walled carbon nanotube (SWCNT) and graphene, subject to mechanical deformation, using phonon wavepacket analysis. Results show that longitudinal acoustic (LA) and transverse acoustic (TA) phonons at low frequencies are transmitted more effectively through the SWCNT-graphene junction when the junction is deformed. As low-frequency phonons in LA and TA modes are major energy carriers, it is expected that thermal transport across the SWCNT-graphene junction will be more efficient when the junction is deformed. Interfacial thermal resistance across the SWCNT-graphene junction was calculated using reverse nonequilibrium molecular dynamics (RNEMD). The RNEMD results show that the interfacial thermal resistance decreases when the structure is elongated, deforming the junction between the SWCNT and graphene. However, there was no notable difference in the transmission of twisting (TW) and flexural (FO) phonons when the junction was deformed. The study also showed that the transmission of phonon energy through the SWCNT-graphene junction has a slight dependence on the group velocity of phonons, with phonons having higher group velocities transmitting the junction more effectively. The findings of this research will play a significant role in advancing the development of futuristic electronics by providing a tool for developing 3D carbon nanostructures with high thermal performance under mechanical deformation.