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 6×1016cm−3with a maximum atx≊ 0.5, where the conduction switched fromptontype. Silicon doping in the 1017cm−3range provided acceptors up tox≊0.85 for a growth temperature of 430 °C. For higherxvalues conduction was mixed and the Hall‐effect data suggest that an inversion layer of electrons could be present on the surface. ©1996 American Institute of Physics.