Atomic and electronic structures of fluorinated BN nanotubes: computational study.

The atomic and electronic structures of fluorinated BN nanotubes (BNNTs) were investigated by generalized gradient approximation (GGA) density functional theory (DFT). The reaction energies of F2 with pristine single-walled BNNTs to form fluorinated BNNTs are exothermic up to 50% coverage. At lower F coverages (below 50%), fluorines prefer external attachments to boron atoms and stay as far away as possible. At 50% F coverage, fluorines favor attachment to all the boron atoms of the outer surface energetically. Such preferable fluorination patterns and highly exothermic reaction energies hold true for double-walled (and multiwalled) BNNTs when the outer tube surface is considered. Fluorination transforms BNNTs into p-type semiconductors at low F coverages, while high F coverages convert BNNTs into p-type conductors. Therefore, the electronic and transport properties of BNNTs can be engineered by fluorination, and this provides potential applications for fluorinated BNNTs in nanoelectronics.