Effect of annealing on electrical properties of InAsSb films grown on GaAs substrates by molecular beam epitaxy

InAs0.3Sb0.7 layers with mirror-like morphology have been grown on GaAs substrates directly by molecular beam epitaxy. A room-temperature electron Hall mobility of 3×104 cm2/V s has been obtained for a 2.4-μm-thick layer by annealing at 200 °C. For the sample annealed at 200 °C, the electron Hall mobility does not change much with the variation of temperature. When the specimens are annealed at 300 °C, the Hall mobility is lower than that of the specimen without annealing. It can be interpreted by the segregation of Sb and the evaporation of As according to the results of X-ray photoelectron spectrum and the degeneracy of the quality of the film according to double crystal X-ray diffraction.