Undoped homoepitaxial and heteroepitaxial films of MBE grown InSb display n-type bulklike semiconducting properties, e.g., high mobility at 77 K. Epitaxial films with p-type conductivity were grown by in situ doping with Be. Transmission electron microscopy of cross-sectioned films showed that the large lattice mismatch between InSb and GaAs is accommodated by both dislocations and stacking faults. Phase separation at, and near, the surface of InSb–InBi deposits was shown by a combination of scanning electron microscopy, and energy dispersive x-ray analysis.