[01] G. R. Ahmed Jamal, Department of Electrical and Electronic Engineering, University of Asia Pacific, Dhaka, Bangladesh. [02] S. M. Mominuzzaman, Department of Electrical and Electronic Engineering, Bangaldesh University of Engineering and Technology, Dhaka, Bangladesh.

Carbon nanotubes are one of the most intensively studied materials in recent decades. The tight-binding (TB) model of π-bands of graphene using the zone-folding approximation has been widely used for modeling electronic band structure of single-wall carbon nanotube (SWCNT) due to its simplicity and low computational cost. However, thorough investigation and detailed comparison of the result from this theoretical model with various recent optical spectroscopic experiments reveals that TB models fails quantitatively and in some cases qualitatively to predict different optical transition energies in SWCNTs. Many authors discussed this issue through theoretical and experimental results and showed the limitation of TB model in describing SWCNTs. The purpose of this work is to discuss various limitations of TB model of SWCNTs along with main theoretical factors that limit this model. This work will presents a summary and review of some important previous research works by different authors highlighting the limitations of Tight-binding (TB) model, especially its nearest-neighbor approximation. This work will also focus on findings by various researchers regarding the main factors that cause the tight binding model given electronic band structure and corresponding transition energies to deviate from experimental results. This review work concludes that the TB model greatly fails in describing SWCNTs.

Carbon Nanotube, SWCNT, Tight Binding Model, Optical Transition Energy, Chiral Index

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