Study of electronic and optical properties of fullerene nanotube under high pressure

The modelling of the geometric structure, vibrational and electronic proper ties of a single-wall fullerene nanotube versus the external pressure is ca rried out. It is shown that the presence of a heptagon-heptagon pair as a d efect in the structure of this nanotube leads to the formation of a semicon ductor-semiconductor heterojunction with different values of the gap. The o btained theoretical results are compared with available experimental data.