Klimeck G., Oyafuso F., Boykin T.B., Bowen R.C., von Allmen P.
NASA, Jet Propulsion Laboratory, US
Keywords: boundary condition, disorder, linewidth, quantum dot
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.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2003 Nanotechnology Conference and Trade Show, Volume 2
Published: February 23, 2003
Pages: 129 - 132
Industry sector: Advanced Materials & Manufacturing
Topics: MEMS & NEMS Devices, Modeling & Applications, Nanoelectronics
ISBN: 0-9728422-1-7