Molecular beam epitaxial growth of high electron mobility InAs/AlGaAsSb deep quantum well structures

We investigated InAs deep quantum well structures made from InAs/AlGaAsSb materials on GaAs substrates by molecular beam epitaxy. By accurately controlling As-4/Sb-4 and As-4/In beam flux ratios, we were able to grow the high-quality crystals of AlGaAsSb and InAs. Very high electron mobility Of more than 32,000 cm(2)/Vs were obtained at room temperature. It was found that the optimum beam-equivalent-pressure (BEP) ratio of As-4/In for growing an InAs quantum well layer is 110 to get the highest electron mobility. Moreover, a strong photoluminescence (PL) peak of AlGaAsSb band-edge emission at 10 K was observed around 1.2 eV. We determined that the optimum As-4/Sb-4 BEP ratio is 6.7 for AlGaAsSb from the full width at half-maximum of PL peaks and electrical characteristics. We also observed the blue shifted PL of AlGaAsSb as the As-4/Sb-4 BEP ratio decreased.