First Principle Study of Graphene-Carbon Nanotubes Hybrid (GCH) Structure for Advanced Nanoelectronics Devices

Although graphene and carbon nanotubes (CNT) exhibit remarkable electronic and mechanical properties, these two carbon allotropes face limitations due to their nanoscale size. The combination of graphene and CNT are suggested to overcome the problem of bundling and stacking in CNT and graphene which limit their performance. First principle study is carried out on the electronic properties of graphene-carbon nanotubes hybrid (GCH) structure using BIOVIA Material Studio software. Density Functional Theory (DFT) is used to calculate its band structure and density of states. The results show that when semiconducting CNT combine with graphene, its band gap is reduced compare to the pristine CNT. However, when metallic CNT is combine with graphene, the changes in band gap is depend on CNT's chirality. Chiral CNT will decrease the band gap of GCH, zigzag CNT causes not much changes in its GCH, while armchair CNT will increase the band gap of its GCH. Therefore, the result shows that it is possible to tune the band gap of GCH by combining graphene sheet with different type of CNT depending on our needs.