Dresden 2011 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 85: Poster Session II
HL 85.94: Poster
Donnerstag, 17. März 2011, 18:00–21:00, P4
Atomistic tight binding models of semiconductor quantum dots — •Elias Goldmann and Frank Jahnke — Institut für Theoretische Physik, Universität Bremen, 28359 Bremen
In recent years, semiconductor nanostructures such as quantum dots have been the subject of intense theoretical and experimental research due to their large potential for next generation device applications.
We present results of an atomistic empirical tight-binding model (ETB) for the calculation of electronic properties of semiconductor nanostructures. We choose a sp3s* basis set localized at each atomic site to correctly reproduce the electronic band structure in the relevant part of the Brillouin-zone and include next-neighbour-interaction as well as spin-orbit-coupling.
A Jacobi-Davidson algorithm in connection with the folded spectrum method is used to compute the eigenstates and eigenenergies of the resulting TB-Hamiltonian of the supercell that contains about 4·105 atoms.
Within this ETB model we investigate the electron and hole wavefunctions and confinement energies of semiconductor nanostructures such as spherical- and pyramidal-shaped self-assembled InAs quantum dots in a InxGa1−xAs quantum well, embedded in a GaAs matrix, which are known as dots-in-a-well (DWELL) structures [1,2]. The influences of dot size, shape and Indium-concentration on the confined states are presented.
[1] S. Krishna, J. Phys. D: Appl.Phys.38 2142 (2005)
[2] A. Amtout et al., J. Appl. Phys. 96 3782 (2004)