CONFINEMENT EFFECTS AND POLARIZATION DEPENDENCE OF LUMINESCENCE FROM MONOLAYER-THICK GE QUANTUM-WELLS

We have investigated the luminescence from monolayer-thick Ge quantum wells pseudomorphic to Si(100) substrates. The electronic structure of these quantum wells was investigated by uniaxial stress, and polariza tion- and temperature-dependent electroluminescence. By identifying th e symmetry and origin of the wave functions involved in the optical tr ansitions, it was found that both the confinement in the thin wells, a s well as the interface between the wells and the surrounding material , play an important role for the emission.