Magnetoresistance Studies of Defect Formation in Cd₃As₂ Thin Films

Epitaxial growth of three-dimensional topological semimetals enables their integration into electronic devices while also permitting careful control of composition to tune its electronic structure. At the same time, heteroepitaxy on dissimilar substrates introduces a range of point and extended defect types. It is critical to now understand the role of defects and disorder introduced by alloying on the magneto-transport properties to inform property control efforts. We study the impact of disorder on the magneto-transport behavior of Dirac semimetal Cd₃As₂, using molecular beam epitaxy to systematically modify native defects and Zn isoelectronic impurity concentrations. We elucidate the extent to which scattering potentials alter the transport properties. As-grown Cd₃As₂ material is well-known to be highly electron doped as a result of As vacancies, and we also demonstrate control over the Fermi level of Cd₃As₂ thin films using tuning parameters uniquely accessible via epitaxial growth.