Molecular beam epitaxial growth and characterization of GaAs/sub 0.5/Sb/sub 0.5/ layers on [111]B InP substrates

GaAs/sub 0.5/Sb/sub 0.5/ layers were grown on [111]B oriented InP substrates by molecular beam epitaxy (MBE). It was found that the Sb mole fraction of the [111] samples is higher than that of [100] samples. Furthermore, the band gap energy of the [111] sample was found to be larger than that of the [100] sample from photoluminescence and optical absorption measurements. The mechanism of the band gap energy shift was discussed based on the spontaneous ordering of alloys.