RADIATIVE ISOELECTRONIC COMPLEXES INTRODUCED DURING THE GROWTH OF SI AND SI1-XGEX/SI SUPERLATTICES BY MOLECULAR-BEAM EPITAXY

Radiative isoelectronic impurity complexes consisting of pairs of Be atoms that bind excitons can be formed in both Si and SiGe/Si superlattices during growth by molecular beam epitaxy. We describe in this letter the conditions under which these radiative complexes can be formed, show that they can be localized in the alloy layers of a superlattice, and demonstrate that the blueshift of the bound-exciton's no-phonon line that occurs for Be-implanted superlattices is absent for grown-in Be complexes. Be densities in excess of 5×1017 cm-3 can be achieved. © 1994 American Institute of Physics.