Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10644524 | Computational Materials Science | 2008 | 5 Pages |
Abstract
We study the electronic structure of semiconductor nanocrystals and nanowires using the tight-binding sp3d5sâ model with all semiconductor atoms dangling bonds passivated by hydrogen atoms. In particular, we show the effect of confinement on the band gap energy of the nanocrystals and nanowires as a function of their radius R. Quantum confinement becomes significant for small nanowires with diameter less than 10Â nm. We also show the confinement-dependence of the position of the energy minimum in the band structure of nanowires. We present the full band structure of Ge and Si nanowires, showing their similarity that the [1Â 1Â 1] wires exhibit a transition from an indirect gap in large wires to a direct one in small wires. We compare the electron band structure calculated using the effective mass approximation with the results obtained by tight-binding method, and we introduce for practical use a semi-analytical model for both the electron effective mass and effective band gap in nanocrystals and nanowires.
Keywords
Related Topics
Physical Sciences and Engineering
Engineering
Computational Mechanics
Authors
Nguyen Hong Quang, Ngo Trung Truc, Yann-Michel Niquet,