Substitutional carbon doping of hexagonal multi-walled boron nitride nanotubes (h-MWBNNTs) via ion implantation

Carbon doping in hexagonal multi-walled boron nitride nanotubes (BNNTs) through ion implantation is successfully achieved. Nuclear reaction analysis confirms that carbon atoms are homogeneously doped into the BNNTs, while Fourier transform infrared spectroscopy reveals that the C–N bonding is produced. Moreover, B–C–N phases are confirmed by X-ray Diffraction and Raman spectroscopy after C⁺ ion implantation. High resolution transmission electron microscopy results show that BNNTs are slightly damaged by C⁺ ion implantation. UV absorption spectra show that carbon doping reduces the band gap of BNNTs from 5.5 to 4.6 eV by increasing C⁺ ion fluence. It is suggested that the bandgap decrease is due to carbon doping as well as defect formation in BNNTs. Carbon implantation in h-BNNTs is proposed to the knockout ejections of B and N atoms by high energy C⁺ ions and consequently make ternary B–C–N structure.