The effect of deformations on electronic structures and optical properties of carbon nanotubes

Electronic structure and optical properties of deformed single-wall carbon nanotubes (SWNTs) varies widely depending on their chirality and deformation mode. Here we present a theoretical framework to analyze the electronic structures and optical properties of deformed SWNTs by quantifying the dispersion relation and density of states (DOS). Based on the tight-binding model of deformed nanotubes under stretching, compression, torsion, and bending, we describe and unify the energy band and optical spectra studies and predict that the shifting, merging, and splitting of Van Hove singularities in the DOS, and optical absorption properties change with strains. The results can be employed to understand and guide experimental studies of electronic and optoelectronic devices based on the carbon nanotubes. (c) 2006 Elsevier B.V. All rights reserved.