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 Zn_xCd_1-xTe buffer layers, miscut substrates, and broadband illumination to study how dislocations, twins, and point defects influence the electron mobility of Cd₃As₂. In conclusion, a combination of defect suppression approaches produces Cd₃As₂ epilayers with electron mobilities upwards of 15000 cm²/Vs at room temperature.