Structural and electronic properties of nanotubes constructed from fragmented fullerenes

2D fullerene-based carbon nanostructures have been recently proposed theoretically. They are conceptually formed by the arrangement of fragments resulting from the unzipping of C ₆₀ molecules. Depending on the details of the assembly, these layer materials exhibit either semiconducting or metallic behavior. Here, we investigate the structural and electronic properties of achiral nanotubes by means of first-principles calculations. We show that this new class of nanotubes are not only energetically stable, but also share many properties similar to those of their 2D counterparts. In addition, the semiconducting cases can exhibit either direct or indirect band gaps. We further show that the electronic properties can be modulated by the presence of a transverse electric field due to an electrostatic potential symmetry breaking. We find that the electric field promotes a radial deformation that grows linearly with the strength of the electric field. In addition, the semiconducting tubes can undergo a semiconducting-metallic transition for a sufficiently large electric field. The study shows that these structures have potential for applications in the area of new nanodevices owing to their tunable band gap.