Modulating electronic properties of carbon nanotube via constructing one-dimensional vdW heterostructures

Controlling charge polarity in the semiconducting single-walled carbon nanotubes (CNTs) by substitutional doping is a difficult work due to their extremely strong C–C bonding. In this work, an inner doping strategy is explored by filling CNTs with one-dimensional (1D)-TM₆Te₆ nanowires to form TM₆Te₆@CNT-(16,0) 1D van der Waals heterostructures (1D-vdWHs). The systematic first-principles studies on the electronic properties of 1D-vdWHs show that N-type doping CNTs can be formed by charge transfer from TM₆Te₆ nanowires to CNTs, without introducing additional carrier scattering. Particularly, contribution from both TM (e.g., Sc and Y) and Te atoms strengthens the charge transfer. The outside CNTs further confine the dispersion of Te-p orbitals in nanowires that deforms the C-π states at the bottom of the conduction band to quasi sp³ hybridization. Our study provides an inner doping strategy that can effectively confine the charge polarity of CNTs and further broaden its applications in some novel nano-devices.