Si-doped and undoped Ga1−xInxSb grown by molecular-beam epitaxy on GaAs substrates

Growth by molecular-beam epitaxy and characterization of Si-doped and unintentionally doped Ga1−xInxSb layers in the full compositional range on GaAs substrates are reported. The grown samples were characterized by reflection high-energy electron diffraction, x-ray diffraction, Hall-effect measurements, and secondary-ion-mass spectroscopy. The unintentionally doped layers had carrier concentrations below 6×1016 cm−3 with a maximum at x≊ 0.5, where the conduction switched from p to n type. Silicon doping in the 1017 cm−3 range provided acceptors up to x≊0.85 for a growth temperature of 430 °C. For higher x values conduction was mixed and the Hall-effect data suggest that an inversion layer of electrons could be present on the surface.