A first principles study of positively charged oxygen vacancies migration in pure and Ge-doped amorphous silica

N. Richard (1) , Sébastien Girard (1) , L. Martin-Samos (2) , A. Boukenter (3) , Y. Ouerdane (3) , J.-P. Meunier (3)

1 DCRE CEA - Département de Conception et Réalisation des Experimentations, CEA-DIF
2 Dipartimento di Fisica
3 LHC - Laboratoire Hubert Curien

Using first principles calculations in a periodic amorphous silica supercell, we calculated the energies and the migration barriers of a positively charged oxygen vacancy in pure and germanium-doped silica. The results show that the puckered and dimer structures of the Si-E' and of the Ge-E' centers are quite similar. The puckered structure of the Si-E' center is not affected by the presence of a germanium atom in its surroundings. Moreover, our calculation shows that in the presence of a germanium atom as first neighbour of an oxygen vacancy, Ge-E' rather than Si-E' are preferably created in silica.

Keywords: Point defects; Density functional theory; Silica

Domains: Optics [physics.optics]

N. Richard, Sébastien Girard, L. Martin-Samos, A. Boukenter, Y. Ouerdane, et al.. A first principles study of positively charged oxygen vacancies migration in pure and Ge-doped amorphous silica. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2008, 266, pp.2719-2722. ⟨10.1016/j.nimb.2008.03.105⟩. ⟨ujm-00297531⟩