Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 71: Poster Session: Graphene / Topological Insulators / Interfaces and Surfaces

HL 71.29: Poster

Mittwoch, 28. März 2012, 16:00–19:00, Poster D

Calculation of valence band offsets from tight-binding band structures — •Daniel Mourad and Gerd Czycholl — Institut für Theoretische Physik, Universität Bremen

The anisotropic valence band offset (VBO) across an interface between two semiconductors A and B is an important material parameter, as it (among others) determines the confinement potential and so e.g. the heterostructure type (I or II) and the level structure in low-dimensional systems. Furthermore, the electronic properties of semiconductor alloys are directly influenced by the VBO. A crucial ingredient in the calculation of the VBO is the use of sufficiently accurate band structures. We present different methods of calculation for the VBO by means of a determination of the charge neutrality level in the framework of an empirical tight-binding model (ETBM).The values will be compared for different sets of material parameters and crystalline phases (zincblende and wurtzite). Furthermore, we will use them to calculate the electronic properties of A_xB_1−x semiconductor alloys.