Regensburg 2007 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 12: Quantum dots and wires: Optical properties I

HL 12.3: Talk

Monday, March 26, 2007, 15:15–15:30, H17

Implementation and application of a k· p-formalism to study electronic structure and Coulomb matrix elements for semiconductor nanostructures — •Oliver Marquardt, Tilmann Hickel, Blazej Grabowski, Sixten Boeck, and Jörg Neugebauer — Max-Planck Institut für Eisenforschung

In order to theoretically predict optical and electronic properties of semiconductor nanostructures such as quantum dots and wires, the eigenvalues and -states of the electrons and holes as well as the Coulomb interaction elements are needed. In order to investigate the effect of shape, size and material composition of larger nanostructures we employed k· p perturbation theory. For this purpose, we have extended our DFT package S/Phi/nX, which was originally developed as a plane wave-pseudopotential code, to calculate k· p kinetic energies both for zincblende and wurtzite structures. This strategy allows us to make use of fast minimization routines and the excellent preconditioners available in plane-wave codes as well as an efficient calculation of the Coulomb matrix in reciprocal space. Based on this approach we have studied a wide variety of quantum dots and nano wires with a particular focus on group-III-nitrides in the cubic and wurtzite phase. The results allow a direct interpretation of recent experiments on nitride based quantum dots.