Strain-induced semiconductor-to-metal transitions in C36-based carbon peapods: Ab initio study

Abstract

We present a density functional study of the band structure and some elastic properties of semiconductor carbon nanotube endohedrally doped with the C36 fullerenes. We found that the electronic states belonging to C36s lied inside the band gap of the pristine tube. External strain applied along the tube axis results in decreasing of the semiconducting gap from 0.3 to 0 eV. Metallic behavior of the strained system is confirmed via the additional calculations of electronic transmission coefficients. Phonons influence is accounted with the molecular dynamics approach. Strain of about 0.04 corresponds to the linear part of stress-strain curve and is found to be sufficient to observe the semiconductor-to-metal transitions at room temperature.