Theory of screw dislocation and chiral angle controlled carbon nanotube growth

This paper has considered the CNT growth as a dislocation facilitated crystal growth, that mimics the Burton-Cabrera-Frank (BCF) theory, well established for 3D-crystals. Achiral SWNTs (zigzag SWNTs) are taken as basis-perfect cylindrical crystal and a SWNT of any chiral angle was viewed as a perfect crystal (or an achiral SWNT) with a screw dislocation. Due to the screw dislocation core location in the vacuum-hollow and the single atomic layer cylindrical structure of the SWNT, there is no penalty energy for the formation of screw dislocation, which allows multiple dislocations to pile together (or the existence of SWNT of any chiral angle). Starting from the screw dislocation model, detailed analysis together with ab initio calculations lead to a conclusion that SWNT growth rate is proportional to the tube chiral angle.