Defects in Cd3As2 Epilayers via Molecular Beam Epitaxy and Strategies for Reducing Them

Molecular beam epitaxy offers an exciting avenue for investigating the behavior of the topological semimetal Cd3As2, by providing routes for doping, alloying, strain engineering, and heterostructure formation. To date, however, minimal exploration has been devoted to the impact of defects that are incorporated into epilayers due to constraints imposed by the substrate and narrow growth window. Here, we use a combination of lattice-matched ZnxCd1-xTe buffer layers, miscut substrates, and broadband illumination to study how dislocations, twins, and point defects influence the electron mobility of Cd3As2. A combination of defect suppression approaches produces Cd3As2 epilayers with electron mobilities upwards of 15000cm2/Vs at room temperature.