Structural and vibrational properties of N, N pairs, and [N,H] complexes in silicon

Abstract

First-principles molecular-dynamics simulations are used to predict the structures and binding energies of interstitial nitrogen (Ni), substitutional nitrogen (Ng), the Njself- interstitial complex, the {Ni,Ni}, {Ni,Ns} = {N2,V}, and {Ng, N J = {N2,V2} pairs (V is the vacancy). The interactions of N with H in Si are studied and the properties of several {N, H} complexes predicted. The dynamical matrices yield many new local and pseudo-locfil vibrational modes associated with the impurities and their Si nearest-neighbors. The unidentified (N, H}-related infra-red absorption line reported by Pajot et al. is assigned to the {Ng, H} complex.