Many-body effects in the excitation spectrum of a defect in SiC

4 páginas, 3 figuras, 2 tablas.-- PACS numbers: 71.35.-y, 71.55.-i, 76.30.Mi
We show that electron correlations control the photophysics of defects in SiC through both renormalization of the quasiparticle band structure and excitonic effects. We consider the carbon vacancy with two possible excitation channels that involve conduction and valence bands. Corrections to the Kohn-Sham ionization levels strongly depend on the defect charge state. Excitonic effects introduce a redshift of 0.23 eV. The analysis reassigns excitation mechanism at the thresholds in photoinduced paramagnetic resonance measurements
We acknowledge funding by the Deutsche Forschungsgemeinschaft (BO1851/2), Spanish MEC (FIS2007-65702-C02-01), ACI-promciona project (ACI2009-1036), and ‘‘Grupos Consolidados UPV/EHU del Gobierno Vasco’’ (IT-319-07), the European Community through e-I3 ETSF project (Contract No. 211956), and support by the Barcelona Supercomputing Center, ‘‘Red Espanola de Supercomputacion.’’