Low temperature photoluminescence of n-type GaInAsP layers grown on InP by liquid phase epitaxy

Publisher Website
Google Scholar
Abstract
Layers of the quaternary alloy GaxIn1−xAsyP1−y (x∼0.1, y∼0.3) were grown on InP (100) substrates by super-cooling liquid phase epitaxy. Tellurium was used for n-type doping in the range 8×1017–5×1019 cm−3. A good homogeneity of the composition of the layers was obtained at the surface. No microprecipitates of tellurium were detected by scanning electron microscope. Systematic studies of luminescence at low temperature were used to characterize the samples, with a particular attention focused on the degeneracy of the conduction band. Calculations of the line shapes were performed based on a recombination mechanism involving acceptor-like states of the valence band and conduction band filling effects. Good agreement was obtained between calculated and experimental line shapes. The Fermi level in quaternary alloys is found to be lower than predicted by theoretical calculations using band structure properties developed in the past for definite III-V compounds such as GaAs and InP. It is suggested that this could be related with disorder electronic effects.