First-principles study of location of Er(3+) ion-relationship to understanding of hyperfine interactions in the optoelectronic erbium-silicon system

The importance of hyperfine interactions in the Erbium-Silicon system is underscored by our first-principles Hartree-Fock Cluster investigations on the location of Erbium in Silicon. Our theoretical studies show that both substitutional and tetrahedral interstitial sites are stable for Er(3+) ion with the latter having a larger binding energy. This conclusion is not completely supported by channeling experiments. It is suggested that Mossbauer measurements on (166)Er isotope would be valuable to compare experimental results with theoretical predictions of the hyperfine interactions of both magnetic and quadrupolar types to provide additional information about the location of Er(3+)