Single-walled MoTe(2) nanotubes.

The structural, electronic, and mechanical properties of single-walled MoTe(2) nanotubes are investigated using density functional theory. All large-diameter MoTe(2) nanotubes are found to be narrow-gap semiconductors, whereas small-diameter nanotubes are found to be less stable compared to large-diameter nanotubes. Notably, the armchair MoTe(2) nanotubes exhibit an indirect band gap, whereas the zigzag nanotubes exhibit a direct band gap. The band gap decreases with decreasing diameter of the tube or if the tube is under compression or elongation in the axial direction. Young's modulus of MoTe(2) nanotubes is calculated and is found to be dependent on the diameter and chirality of the tubes. The armchair nanotubes are stiffer than the zigzag nanotubes with the same diameter. Compared to the homologous MoTe(2) nanotubes, the MoTe(2) nanotubes are softer due to less strain-energy cost in forming the nanotube structures.