Electronic and optical properties of single-walled silicon nanotubes: the sp3 tight-binding model | ||
| The Modares Journal of Electrical Engineering | ||
| Article 4, Volume 15, Issue 3, 2015, Pages 27-31 PDF (597.14 K) | ||
| Authors | ||
| Mohsen Heidari1; Vahid Ahmadi* 2; Sara Darbari3 | ||
| 1دانشجوی دکتری دانشکده برق و کامپیوتر، تربیت مدرس | ||
| 2Tarbiat Modares University | ||
| 3استادیار دانشکده برق و کامپیوتر، تربیت مدرس | ||
| Abstract | ||
| In this paper, we investigate the curvature effects on the electronic band structure and dielectric function of single-walled silicon nanotubes and carbon nanotubes, based on tight-binding method. The curvature nature of nanotubes causes radius-dependent σ-π-orbital hybridization which leads to optimization of tight-binding model for each radii. First, the effects of orbitals overlap and the structural optimization on the electronic band structure of small radius nanotubes are investigated. Second, the imaginary part of dielectric function of nanotubes, which is related to optical absorption coefficient, is obtained by calculating the interband optical matrix elements using gradient approximation. It is shown that the σ-π-tight-binding model optimization due to the curvature effects, introduces small changes to the optical transition energies obtained by simple π-band tight-binding model. The results show that the curvature effects are more important in small radius tubes. | ||
| Keywords | ||
| silicon nanotube; silicene; Carbon nanotube; curvature effect; electronic properties; optical properties; density function theory | ||
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