Computational and theoretical study of B-doped achiral single-walled carbon nanotubes: A nonresonant polarized Raman analysis

Abstract

Tailoring the unique properties of carbon nanotubes should be studied. However, chemical doping by incorporation of boron atoms into carbon nanotubes (CNTs) has been examined as a powerful tool which provides various advantages. In this paper, we review several recent researches by which to dope carbon nanotubes by boron atoms into the sp2 carbon lattice, the properties induced by boron doping, and promising applications of this type of doping nanomaterials. We envisage that intrinsic boron doping will accelerate both scientific and industrial developments in the area of CNTs and nanotechnology in a later researches. Furthermore, the calculations of the polarized Raman active modes in boron-doped achiral single-walled carbon nanotubes are performed in the framework of the force constants model. Moreover, The spectral moment’s method was used in order to calculate the nonresonant Raman spectra for systems contain several atoms, it is shown that a powerful tool. The variations of the Raman spectra as a function of the rate doping of boron atoms are identified and the relative intensity ratio between Raman active modes of D and G bands has been analyzed. Raman spectroscopy analysis reveals mathematical expressions, it was derived to describe the dependence of the Radial Breathing Modes (RBM) with the diameter and the B-doping rate. It is shown that the diameter scale in Kataura’s plot must be converted into in order to directly compare to the experimental Raman spectra. Such conversion must be performed by using the relation ωRBM=218−1,2τD. Once this adjustment is done, one is ready to associate each pair (ωRBM,τ) to a specific (n, m) if the ωRBM values are well known. For example the RBM modes at 165 cm−1 and 133 cm−1 are assigned to the single walled carbon nanotube (10,10) and BC3 nanotube (5,5) respectively. The results of this work provide the (n, m) dependence of the RBM of SBCNTs, it gives good benchmark for performing (n,m) assignment of doped SWCNTs.