Molecular beam epitaxy of Cd3As2 on a III-V substrate

Epitaxial,strain-engineered Diracsemimetalheterostructures promise tuning of the unique properties of these materials. In thisstudy, we investigate the growth of thin films of the recently discovered DiracsemimetalCd3As2 by molecular beam epitaxy. We show that epitaxialCd3As2 layers can be grown at low temperatures (110 °C–220 °C), in situ, on (111) GaSbbuffer layersdeposited on (111) GaAs substrates. The orientation relationship is described by(112)Cd3As2|| (111) GaSb and [11¯0]Cd3As2|| [1¯01]GaSb. The films are shown to grow in thelow-temperature, vacancy ordered, tetragonal Diracsemimetal phase.They exhibit high room temperature mobilities of up to 19300 cm2/Vs, despite athree-dimensional surface morphology indicative of island growth and the presenceof twin variants. The results indicate that epitaxialgrowth onmore closely lattice matched buffer layers, such as InGaSb or InAlSb, which allow for imposingdifferent degrees of epitaxial coherency strains, should be possible