Magneto-Optical and Transport Properties of GaAs/AlAs:Yb Superlattices

We have grown Yb-doped GaAs/AlAs superlattice samples with molecular beam epitaxy method and measured magnetic field dependence of photoluminescence and resistance up to 15 T. Two additional PL peaks in the mid-gap energy region were found only in the case of selective excitation of the well layer. These peaks show anomalous oscillatory behavior, which can be understood as high density accumulation of two-dimensional electrons. These results indicate that photoexcited electron-hole system in the well layers rapidly transferred to Yb-related traps in the barrier layers.