First-principles study of impurity segregation in edge dislocations in Si

Using ab initio calculations, the segregation of As, Ga, and Ge atoms in the core regions of perfect edge dislocations in Si is examined. When all nearest neighbors of an impurity are Si atoms, As favors the core site at maximum compression and has a segregation energy of 0.25 eV/atom. Ga and Ge impurities favor sites under maximum tension and have segregation energies of 0.44 and 0.19 eV per atom, respectively. For As impurities, however, a pairing mechanism yields an even larger segregation energy of 0.64 eV/atom.