It is shown that the optical activation of Yb in GaAs and low-dimensional G
aAs/GaAlAs structures can be achieved by forming three-component (Yb+S/Se/T
e+O) luminescence centers based on the Yb3+ ion. A correlation between the
characteristics of these centers and the parameters of the chalcogen coacti
vators is discovered. Oxygen is shown to play a decisive role in transferri
ng the energy of electron-hole pairs to the luminescence centers. (C) 1999
American Institute of Physics. [S1063-7826(99)01106-0].