Dresden 2017 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 47: Topical session: Data driven materials design - ab initio materials design

MM 47.2: Talk

Wednesday, March 22, 2017, 16:15–16:30, BAR 205

Evolution of defect populations in silicon carbide : coupling ab initio energetics, charged defects and rate theory — •Guido Roma, Thomas Jourdan, Quentin Bouton, Jean-Paul Crocombette, and Fabien Bruneval — DEN-Service de Recherches de Métallurgie Physique, CEA, Université Paris-Saclay, 91191 Gif sur Yvette, France

Ab initio based evolution of defect populations using stochastic methods or rate theory has been developed since at least a decade and has provided the explanation of the evolution of material properties of irradiated materials [1]. Its application concerns, however, mostly metals. Although applications to semiconductors or insulators exist [2], they overlook in most cases the variety of charge states of point defects. We discuss here an approach to overcome this limitation in the case of silicon carbide, where we dispose of a relatively complete database of defect energetics. We present some results of rate theory simulations for silicon carbide where intrinsic defects are supersaturated, as it happens for example under or after electron irradiation. In particular, we show examples where the mutual influence of doping and kinetics in the material matters, and we revisit our previous prediction of SiC nanodecomposition driven by vacancy-interstitial recombinations [3], where electrostatic effects were neglected. We discuss also the possibility of coupling this approach with the simulation of spectral properties, with the example of Raman spectra.