Nanotech 2003 Vol. 2
Nanotech 2003 Vol. 2
Technical Proceedings of the 2003 Nanotechnology Conference and Trade Show, Volume 2

Nano Scale Device Modeling Chapter 3

Study of Alloy Disorder in Quantum Dots through Multi-million Atom Simulations

Authors: G. Klimeck, F. Oyafuso, T.B. Boykin, R.C. Bowen and P. von Allmen

Affilation: NASA, Jet Propulsion Laboratory, United States

Pages: 129 - 132

Keywords: quantum dot, boundary condition, linewidth, disorder

Abstract:
A tight binding model which includes s, p, d and s* orbitals is used to examine the electronic structures of an ensemble of dome-shaped In0.6Ga0.4As quantum dots. Given ensembles of identically sized quantum dots, variations in composition and configuration yield a linewidth broadening of less than 0.35 meV, much smaller than the total broadening determined from photoluminescence experiments. It is also found that the computed disorder induced broadening is very sensitive to the applied boundary conditions, so that care must be taken to ensure proper convergence of the numerical results. Examination of local eigenenergies as functions of position shows similar convergence problems and indicates that an inaccurate resolution of the equilibrium atomic positions due to truncation of the simulation domain may be the source of the slow ground state convergence.

Study of Alloy Disorder in Quantum Dots through Multi-million Atom Simulations

ISBN: 0-9728422-1-7
Pages: 600