Undoped Ga_1-xIn_xSb Grown by Molecular Beam Epitaxy on GaAs Substrates

Abstract

Growth by molecular beam epitaxy and characterisation of unintentionally doped Ga 1- x In x Sb layers in the full compositional range on GaAs substrates are reported. The grown samples were characterised by reflection high-energy electron diffraction, X-ray diffraction and Hall-effect measurements. The layers had carrier concentrations below 6 × 10 16 \kubik with a maximum at x ≈0.5, where the conduction switched from p -type to n -type. Temperature-dependent Hall-effect measurements together with mixed-conduction simulations showed that the n -type behaviour is caused by intrinsic electrons and the large electron-hole ratio rather than donor centres.