Ab initio study of the diffusion barriers for iron and chromium impurities in silicon

This work presents a theoretical study of iron and chromium impurities located at substitutional site and their complex with a vacancy by the density functional theory. Diffusion barriers separating the recombination centers such as the Fei-V(Cri-V) and FeSi(CrSi) has been studied by the nudged elastic band method for positively charged and neutral states of these defects. We found that the barrier heights separating FeSi(CrSi) from interstitials are ≥1.0 eV, which complicates transition of the substitutional impurities to interstitial sites.