Band-gap modulation of carbon nanotubes with Haeckelite structure under a transverse electric field: A first principle study

We have addressed the effect of transverse electric field on chiral carbon nanotubes with two types of Haeckelite structure. We have successfully verified that chiral (10, 5) carbon nanotube with different types of Haeckelite structure react quite differently in response to a transverse electric field. The band gap varies quadratically for small electric fields and becomes monotonically linear upon increasing the transverse electric filed. Two main interesting phenomena were observed when a transverse electric field applied on the nanotubes with Haeckelite structures. First of all, the semiconductor-metal transition existed regardless Haeckelite structure type; although some variations in the band-gap between the pristine nanotubes and nanotubes with both types of Haeckelites structure. This variation is an indication for strong effect caused by introducing this special type of defects to the nanotube surface. Second, the variations in the band-gap for the pristine nanotube and the two nanotubes with Haeckelite structure have the same trend, even though each type of defects have distinct band gap values under various strengths of the external transverse electric field.