Cnt-Graphene Heterostructures: First-Principle Study Of Electrical And Thermal Conductions

Heterostructures of carbon nanotube on graphene, CNT-graphene, with two graphene layers connected by a CNT normal to the graphene planes, are investigated using first-principle calculations, leading to computed density of states (DOS) and electron transmission spectra. Based on these results, the structure consisting of graphene and a (4,4) CNT is determined to be metallic while that of graphene and (8,0) CNT semiconducting. Multiple peaks are observed in the transmission spectrum of both heterostructures, which depend on the width of graphene. Further, it is found that the heterostructures are three-dimensional thermal conductors, although the resistance is higher than that of pure graphene or CNT. These results lay the foundation for further studies of CNT-graphene as a potential all-carbon interconnect building block.