Structural properties and growth mechanism of Cd3As2 nanowires

Cadmium arsenide (Cd3As2) is a material well-known for its very high room-temperature carrier mobility. Recently, it has also been shown to be a three-dimensional Dirac semimetal—the three-dimensional analogue of graphene. Here, we present a detailed structural study of the self-catalyzed growth of Cd3As2 nanowires. The crystal structure is confirmed using X-ray diffraction and transmission electron microscopy. Scanning electron microscopy and energy-dispersive X-ray spectroscopy are used to gain insight into the vapor-solid growth mechanism. The role of group II and V elements is reversed in contrast to III-V and other II-V systems, and the tips are found to be As-rich.