Molecular beam epitaxy of Cd3As2 on a III-V substrate

Epitaxial, strain-engineered Dirac semimetal heterostructures promise tuning of the unique properties of these materials. In this study, we investigate the growth of thin films of the recently discovered Dirac semimetal Cd3As2 by molecular beam epitaxy. We show that epitaxial Cd3As2 layers can be grown at low temperatures (110 degrees C-220 degrees C), in situ, on (111) GaSb buffer layers deposited on (111) GaAs substrates. The orientation relationship is described by (112) Cd3As2 parallel to (111) GaSb and [1 (1) over bar0] Cd3As2 parallel to [(1) over bar 01](GaSb). The films are shown to grow in the low-temperature, vacancy ordered, tetragonal Dirac semimetal phase. They exhibit high room temperature mobilities of up to 19 300 cm(2)/ Vs, despite a three-dimensional surface morphology indicative of island growth and the presence of twin variants. The results indicate that epitaxial growth on more closely lattice matched buffer layers, such as InGaSb or InAlSb, which allow for imposing different degrees of epitaxial coherency strains, should be possible. (C) 2016 Author(s).