Molecular-dynamics study of the vacancy-hydrogen and vacancy-deuterium complexes in silicon

Abstract

In order to understand the behavior of vacancy-hydrogen complexes ({V,H-n}, n = 1,...,4) in silicon, we have studied the equilibrium configurations and the vibrational modes of the (V,H,) complexes in silicon using HnSi63 (n = 1,...,4) supercells with the pseudo-atomic orbital ab-initio molecular-dynamics theory developed by Sankey and co-workers. It has also been investigated the vibrational frequencies of vacancy-deuterium complexes ({V,D-n}, n=1,...,4) in silicon. Since the mass of deuterium is twice that of hydrogen, we can easily expect that the vibrational frequency of {V,D-1} is smaller by a factor of 1/root(2) than that of {V,H-1}. However, it is not easy to expect the vibrational frequencies of the {V,D-n} with n = 2,3,4. The calculated results are presented for the equilibrium configurations and the vibrational modes of the {V,H-n} and {V,D-n} complexes.