Optical matrix elements in tight-binding approach of hydrogenated Si nanowires

The dependence of the imaginary part of the dielectric function on the quantum confinement within two different schemes: intra-atomic and interatomic optical matrix elements are applied and compared. The optical spectra of Si nanowires are studied by means of a semi-empirical sp3s* tight-binding sup...

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Bibliographic Details
Authors: JOSE ALEJANDRO DIAZ MENDEZ, MIGUEL CRUZ IRISSON
Format: article
Status:Versión aceptada para publicación
Publication Date:2009
Country:México
Institution:Instituto Nacional de Astrofísica, Óptica y Electrónica
Repository:Repositorio Institucional del INAOE
Language:English
OAI Identifier:oai:inaoe.repositorioinstitucional.mx:1009/1228
Online Access:http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1228
Access Level:Open access
Keyword:info:eu-repo/classification/Silicon nanowires/Silicon nanowires
info:eu-repo/classification/Tight-binding approach/Tight-binding approach
info:eu-repo/classification/Dielectric function/Dielectric function
info:eu-repo/classification/cti/1
info:eu-repo/classification/cti/22
info:eu-repo/classification/cti/2203
Description
Summary:The dependence of the imaginary part of the dielectric function on the quantum confinement within two different schemes: intra-atomic and interatomic optical matrix elements are applied and compared. The optical spectra of Si nanowires are studied by means of a semi-empirical sp3s* tight-binding supercell model. The surface dangling bonds are passivated by hydrogen atoms. The results show that although the intra-atomic matrix elements are small in magnitude, the interference between these terms and the interatomic matrix elements contributes with nearly 25% of the total absorption. Thus, a quantitative treatment of nanostructures may not be possible without the inclusion of intra-atomic matrix elements.