Tight-binding parameterization of alpha-Sn quasiparticle band structure

The diamond structure of tin (alpha-Sn) can be stabilized in namocrystals embedded in a suitable host. We developed highly accurate parameterizations for tight-binding simulation of such structures incorporating Strain and spin-orbit interaction. Parameters are obtained by fitting to ab initio GW quasiparticle band structures of unstrained alpha-Sn as well as geometries under uniform compressive or tensile strain. The optical response calculated from this fit is in excellent agreement with experiments. As an application, confinement induced band gaps in strained and unstrained 3 nm nanocrystals are computed. It is found that compressive and tensile strain raises and lowers the gap, respectively. (C) 2009 Elsevier Ltd. All rights reserved.