Undoped Ga1-xInxSb grown by molecular beam epitaxy on GaAs substrates

Growth by molecular beam epitaxy and characterisation of unintentionally doped Ga1-xInxSb 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 x 10(16) cm(-3) with a maximum at x approximate to 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.