Regensburg 2013 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 29: Poster Session: Spintronics; Spin-controled transport; Topological insulators; Interfaces / Surfaces; Magnetic semiconductors

HL 29.24: Poster

Monday, March 11, 2013, 16:00–20:00, Poster A

Electronic Properties of Si/ZnO Interfaces by ab initio Quasiparticle Calculations — •Benjamin Höffling and Friedhelm Bechstedt — Institut für Festkörpertheorie und -optik and European Theoretical Spectroscopy Facility (ETSF), Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany

Transparent Conducting Oxides like ZnO are routinely used in Si-based photovoltaics. However, key electronic properties are still controversially discussed in the literature. Modern ab-initio simulations can help to address this problem.

The applicability of these methods rests on the construction of realistic atomic models for such systems. Modeling interfaces between materials with different crystal structures, bonding mechanisms and chemical character within the repeated-slab supercell method is a particularly difficult challenge.

We develop a method for the construction of atomic models of heterostructural interfaces based on coincidence lattices, maximum bond saturation, and total energy minimization, which enables us to construct model geometries for the interface between diamond structure Si and wurtzite-ZnO. In particular we investigate the Si(001)/ZnO(20-23) by means of density functional theory (DFT). We predict electronic properties of the interfaces using both DFT and modern quasiparticle theory based on semilocal exchange-correlation functionals. We examine band discontinuities and interface states. The influence of dangling bond passivation, strain, and charge transfer is studied by their respective influence on the electronic density of states.