Investigation of the interaction between hydrogen and screw dislocation in silicon by first principles calculations

Laurent Pizzagalli (1)

1 PhyMat - Laboratoire de Physique des Matériaux

The stability of atomic and molecular hydrogen in the vicinity of a screw dislocation in silicon has been investigated using first-principles calculations. Lowest energy configurations are obtained for H atoms located into the dislocation core, suggesting that the segregation of hydrogen is favoured into the dislocation core. It is found that a spontaneous dissociation of H$_2$ could occur in the dislocation core. Finally, the variation of the interaction energy between hydrogen and the dislocation core as a function of the separating distance has been calculated. There is no sizeable interaction variation for H$_2$. However, in the case of a single H, an inverse law has been obtained which can be explained by the anisotropic stress field generated by the insertion of H in the silicon lattice.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Laurent Pizzagalli. Investigation of the interaction between hydrogen and screw dislocation in silicon by first principles calculations. Journal of Physics: Condensed Matter, 2009, 22, pp.035803. ⟨10.1088/0953-8984/22/3/035803⟩. ⟨hal-00728916⟩