Berlin 2015 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 81: Heterostructures and interfaces
HL 81.8: Vortrag
Donnerstag, 19. März 2015, 17:00–17:15, EW 201
A molecular statics study of strain fields and defect stability in axial-heteroepitaxial nanopillars — •Thomas Riedl1,2 and Jörg Lindner1,2 — 1University of Paderborn, Department of Physics, Warburger Straße 100, 33098 Paderborn, Germany — 2Center for Optoelectronics and Photonics Paderborn (CeOPP), Warburger Straße 100, 33098 Paderborn, Germany
Semiconductor nanopillars containing a heteroepitaxial junction in the axial direction are attractive for electronic and optoelectronic applications, owing to the high elastic relaxation of misfit strains and the possibility to modify the electronic band structure by means of strain. Compared to planar substrates axial-heteroepitaxial nanopillars can accomodate larger misfits without formation of misfit-related defects. Previous studies predicting the stability of misfit dislocations in axial-heteroepitaxial nanopillars or nanowires used different variants of analytic continuum theory or the finite element method. In the present contribution we investigate the strain fields and the stability of misfit dislocations in zinc blende InAs/GaAs nanopillars by means of atomistic molecular statics simulation. Because of its applicability to various bonding configurations and availability of suitable parametrizations the Tersoff potential is employed. The stability of the coherent defect-free state and of the dislocated state is analyzed in terms of the pillar dimensions and the dislocation configuration, i.e. dislocation type and position for both [001] and [111] pillar axis directions. The results are compared with the predictions of continuum approaches and with experiments reported in the literature.