Binding and migration paths of Au adatoms on the GaAs(001) surface

FWN – Publicaties zonder aanstelling Universiteit Leide

Theory of hydrogen complexes in Mn(x)Ga(1-x)As dilute magnetic semiconductors

Atomic hydrogen diffuses in semiconductor lattices and binds to impurities by forming complexes that can lead to a full neutralization of the impurity effects. In the present paper, the structural, vibrational, electronic and magnetic properties of complexes formed by H in the Mn xGa1-xAs (x=0.03) dilute magnetic semiconductor have been investigated by using first-principles DFT-LSD and LDA+U theoretical methods. The results account for recent experimental findings showing a H passivation of the electronic and magnetic properties of Mn in GaAs. Moreover, they show that electron correlation has crucial effects on the properties of H-Mn complexes

SILICON-HYDROGEN-ACCEPTOR COMPLEXES IN CRYSTALLINE SILICON

An extensive investigation of the equilibrium sites of H in p-type silicon has been performed in order to clarify the influence of the specific impurity on the geometry of the silicon-hydrogen-acceptor complexes. Previous studies focused onto the B and Al cases have been extended to the isovalent acceptors Ga and In, making clear the relevance of the impurity atomic size. The on-axis BC site is shown to be a marginal equilibrium position, which evolves toward an off-axis position as soon as the acceptor size exceeds that of B. A novel H metastable site has been estimated, only in Si:In, at the AB-In site, thus suggesting a dependence of H equilibrium sites on the full chemistry of the impurity. These results account well for far-infrared measurements in Si:Al and Si:Ga, as well as for perturbed gamma-gamma-angular correlation results in Si:In