In the study, the structural and electronic properties of zigzag Graphdiyne nanotube (2, 2) in the pure state and in the presence of lithium and nitrogen impurities were studied using the density functional theory method. The structure investigation shows that the pure Graphdiyne nanotube is a semiconductor with a direct band gap of 0.65eV at gamma point. By inserting the lithium and nitrogen impurities, nanotubes exhibit the metallic behavior. The optical properties of all nanotubes above-mentioned were examined and computed using SIESTA package and based on Kramers–Kronig relations. Optical investigations show that placing the lithium atom in the center of the nanotube has little effect on the optical properties, but, by substituting the nitrogen atoms for carbon atoms, the optical properties significantly change.

Graphdiyne Nanotube, Impurities, DFT, Optical Properties