Using Zintl-Klemm intermetallics in oxide-semiconductor heteroepitaxy

Abstract

We propose using the Zintl-Klemm (Z-K) bonding to engineer transition layers that provide wetting between ionic oxides and covalent semiconductors to ensure two-dimensional epitaxial growth. Using density functional theory to test this concept, we consider the thermodynamics of wetting at the GaAs/SrTiO3 interface, and identify Sr aluminide SrAl2 as the Z-K wetting layer. We discuss the atomic structure and bonding at the interface, and estimate the conduction band discontinuity to be 0.6 eV, in good agreement with recent experiment.