Growth and characterization of a GaAs/AlAs superlattice with variable layer thicknesses
Growth and properties of a short-period (GaAs)n/(AlAs)m superlattice grown by molecular beam epitaxy on (100) GaAs are reported. The structure of the superlattice with variable (n∼m = to 15) layer thicknesses was studied by double crystal x-ray diffraction. Special care was taken to exclude the effect of several parameters; e.g., the inaccuracy of the lattice mismatch between the AlAs and GaAs layers, which may cause errors in the determination of the layer thicknesses. The electronic properties of the superlattice were studied by photoreflectance and photoluminescence. The γ-X band crossing was found to occur at 13.5 monolayers at 12K.