Engineering the band gap of BN and BC2N nanotubes based on T-graphene sheets using a transverse electric field: Density functional theory study

A new class of nanotubes formed by rolling boron nitride (BN) and boron carbonitride (BC2N) sheets in the form of T-graphene is suggested in this work. The structural and electronic properties of these nanotubes, named T-BNNTs and T-BC2NNTs, are systematically studied by density functional theory (DFT) calculations. The tubes with different chirality and size are considered. Their structural stability is evaluated by calculation of cohesive energy and ab-initio molecular dynamics simulation. The results confirm the thermal stability of the considered T-BNNTs and T-BC2NNTs. The calculated electronic band structures and density of states reveal that the T-BNNTs are insulators, independent of their size and chirality. The T-BC2NNTs show both metallic and semiconducting properties. Our results indicate that the electronic properties of T-BNNTs and T-BC2NNTs can be successfully tuned by applying an external electric field, which makes the application of these tubes in nanoelectronic devices more promising.