Berlin 2008 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 42: Optical Properties of Quantum dots: Theory and Simulation

HL 42.6: Talk

Thursday, February 28, 2008, 11:00–11:15, EW 201

Plane-Wave-implementation of the k· p-formalism including strain and piezoelectricity to study the optoelectronic properties of semiconductor nanostructures — •Oliver Marquardt, Tilmann Hickel, and Jörg Neugebauer — Max-Planck-Institut für Eisenforschung

Optical properties of semiconductor nanostructures such as quantum dots and wires are a direct consequence of their shape, size and material composition. The k· p formalism provides a real space approach to compute relevant parameters of nanostructures as e.g. needed to simulate optoelectronic devices such as light and laser emitting diodes. Contributions like strain and piezoelectric potentials entering the k· p formalism are typically calculated using continuum elasticity theory.
We have reformulated this approach into a mixed real / reciprocal space formalism and implemented it into our plane-wave DFT-package S/Phi/nX. This allowed us to make efficient use of the existing highly optimized minimization routines as well as the efficient preconditioner techniques in a plane-wave basis set.
We investigate different nanostructures with a focus on the III-nitride materials in the zincblende and wurtzite phase. A detailed comparison to approaches resolving fully the atomistic structure will be shown in order to verify the validity of our approach. Further the influence of the spin-orbital coupling which has been commonly neglected is shown to lift the artificial degeneracy of the hole ground state.