1. First principles many-body calculations of electronic structure and optical properties of SiC nanoribbons
- Author
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Nikhil V. Medhekar, Vaideesh Loganathan, Naresh Alaal, and Alok Shukla
- Subjects
GW approximation ,Nanobelts ,Materials science ,Acoustics and Ultrasonics ,Absorption spectroscopy ,Hydrogen ,Band gap ,Silicon-Carbide Nanoribbons ,Carbon Nanoribbons ,FOS: Physical sciences ,chemistry.chemical_element ,02 engineering and technology ,Electronic structure ,01 natural sciences ,Condensed Matter::Materials Science ,Density-Functional Theory ,Excitonic Effects ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,Optical Absorption ,Physics::Atomic and Molecular Clusters ,Physics::Chemical Physics ,010306 general physics ,Electronic band structure ,Band Structure ,Sic ,Condensed Matter - Materials Science ,Nanotubes ,Condensed matter physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Materials Science (cond-mat.mtrl-sci) ,Ab-Initio ,Nanoribbons ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Graphene Nanoribbons ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Transition ,Quasiparticle ,Gw Approach ,0210 nano-technology ,Curse of dimensionality - Abstract
A first principles many-body approach is employed to calculate the band structure and optical response of nanometer sized ribbons of SiC. Many-body effects are incorporated using the GW approximation, and excitonic effects are included using the Bethe-Salpeter equation. Both unpassivated and hydrogen passivated armchair SiC nanoribbons are studied. As a consequence of low dimensionality, large quasiparticle corrections are seen to the Kohn-Sham energy gaps. In both cases quasiparticle band gaps are increased by up to 2 eV, as compared to their Kohn-Sham energy values. Inclusion of electron-hole interactions modifies the absorption spectra significantly, giving rise to strongly bound excitonic peaks in these systems.The results suggest that hydrogen-passivated armchair SiC nanoribbons have the potential to be used in optoelectronic devices operating in the UV-Vis region of the spectrum. We also compute the formation energies of these nanoribbons as a function of their widths, and conclude that hydrogen-saturated ribbons will be much more stable as compared to the bare ones., 18 pages, 7 figures (included)
- Published
- 2016
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