Berlin 2018 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 30: Interfaces

MM 30.4: Talk

Wednesday, March 14, 2018, 11:00–11:15, H 0107

structural prediction of low-energy interface reconstructions of Σ 5 grain boundaries — •lin sun — Institut für Festkörpertheorie und Optik, Friedrich-Schiller-Universität Jena, Germany

We performed ab initio global structural predictions with the minima hopping method of interface reconstructions in three different silicon grain boundaries, Σ5(012), Σ5(031) and Σ5(521). We calculated interface energies and electronic density of states. Compared with locally optimized structures, our new structures have lower total energies and significantly smaller interface energies. We observed some recurrent geometrical features of the lowest energy interfaces: Si atoms prefer to form spiral structures rather than simiple rings. Concerning the electronic properties, defect energy levels in the band gap of locally-optimized interfaces can disappear after interface reconstruction. Our investigation suggests that global structural prediction is extremly important to predict the effect on transport and optical properties of grain boundaries in semiconductors.