In GaAsyN1–y, the presence of a few percent of N induces a large reduction of the GaAs band gap that vanishes upon hydrogenation. In the present Letter, the energetics of N-H complexes and their effects on the band structure of the GaAs0.97N0.03 alloy were

investigated by first-principles density functional methods. It was found that monohydrogen N–H+ and dihydrogen N–H2* complexes were formed depending on doping. Moreover, only N–H2* complexes account for the neutralization of N effects. A model was proposed that clarifies the passivation mechanism of N by H.

Structure and Passivation Effects of Mono- and Dihydrogen Complexes in GaAsyN1-y Alloys. A.A.Bonapasta, F.Filippone, P.Giannozzi, M.Capizzi, A.Polimeni: Physical Review Letters, 2002, 89[21], 216401 (4pp)