External Bias Dependent Direct To Indirect Band Gap Transition In Graphene Nanoribbon

Content Provider	Indian Institute of Science (IISc)
Author	Majumdar, Kausik Murali, Kota Vrm Bhat, Navakanta Lin, Yu Ming
Copyright Year	2010
Abstract	In this work, using self-consistent tight-binding calculations. for the first time, we show that a direct to indirect band gap transition is possible in an armchair graphene nanoribbon by the application of an external bias along the width of the ribbon, opening up the possibility of new device applications. With the help of the Dirac equation, we qualitatively explain this band gap transition using the asymmetry in the spatial distribution of the perturbation potential produced inside the nanoribbon by the external bias. This is followed by the verification of the band gap trends with a numerical technique using Magnus expansion of matrix exponentials. Finally, we show that the carrier effective masses possess tunable sharp characters in the vicinity of the band gap transition points.
File Format	PDF
Journal	PeerReviewed
Language	English
Publisher	American Chemical Society
Publisher Date	2010-08-01
Access Restriction	Authorized
Subject Keyword	Electrical Communication Engineering Others
Content Type	Text
Resource Type	Article