An extended model for chirality selection in single-walled carbon nanotubes.

Abstract

The chirality selective production of single-walled carbon nanotubes (SWCNTs) continues to represent one of the most important technological challenges. In this study, an extended model which considers all steps of the SWCNT growth process, including adsorption, decomposition, diffusion, and incorporation, is applied, for the first time, to obtain chirality selection in the SWCNT populations. We show that the dependence of the population distribution on chirality, defined as a product of the nucleation probability and the growth rate, has a volcano-shape. The model is in good agreement with the reported experimental studies and supports the results which show the surplus of near armchair or near zigzag SWCNTs. The present work emphasizes the role of the catalyst in chirality selection via optimization of chemisorption strength between the carbon species and the catalyst surface needed to achieve stable nucleation and fast growth rates. The obtained results can be used in catalyst designs to define the pathways towards the growth of SWCNTs with specific chiralities exhibiting distinguished electronic properties.