It was noted that radiative iso-electronic impurity complexes, which consisted of pairs of Be atoms which bound excitons, could be formed in both Si and SiGe/Si superlattices during growth via molecular beam epitaxy. Here, the conditions were described under which these radiative complexes could be formed. It was shown that they could be localized in the alloy layers of a superlattice, and it was demonstrated that the blue-shift of the bound-exciton's no-phonon line (which occurred in the case of Be-implanted superlattices) was absent in the case of grown-in Be complexes. It was found that Be densities which exceeded 5 x 1017/cm3 could be obtained.

K.L.Moore, O.King, D.G.Hall, J.Bevk, M.Furtsch: Applied Physics Letters, 1994, 65[21], 2705-7