Lattice‐matched layers of have been grown at 510°C on (100) substrates by molecular beam epitaxy. Epitaxial layers of highly uniform composition were achieved by mixing Ga and In together in a single source, Reproducible flux control was achieved by careful use of a quadrupole mass analyzer. In addition, the morphology, reflection electron diffraction, and electrical properties of epitaxial layers were studied as function of . When the epitaxial layers exhibit mirror‐smooth, featureless morphology devoid of misfit dislocation‐induced crosshatching. Such crosshatching becomes prominent when and . Further, those epitaxial layers which are under tensile stress tend to exhibit cracking when thermally cycled. The best unintentionally doped epitaxial layers had and . double heterostructures have also been fabricated and made to lase at 77°K under optical excitation conditions. These lasers have a threshold of 6.2 kW/cm2 and an output wavelength of about 1.425 μm.