Band Energy Dependence of Defect Formation in the Topological Semimetal Cd3As2

Conference · Wed Nov 15 04:00:00 EST 2023

DOI:https://doi.org/10.1103/PhysRevB.107.224110· OSTI ID:2221845

Brooks, Chase; van Schilfgaarde, Mark; Pashov, D.; Nelson, Jocienne N.; Alberi, Kirstin; Dessau, D. S.; Lany, Stephan

Cadmium Arsenide (Cd3As2) is a prototypical Dirac semimetal that manifests topological properties in a 3D bulk material. In defect-free Cd3As2, the Fermi level lies at a minimum in the density of states at the Dirac point, but experimentally it forms with excess electron carriers and an elevated EF, thereby masking the topological features. To computationally study the self-doping of Cd3As2, we combine density functional theory (DFT) calculations for defect formation energies with quasi-particle self-consistent GW (QSGW) electronic structure calculations. We demonstrate an innate dependence of the point defect formation energies on carrier concentrations and use the QSGW calculated density of states to extrapolate formation energies to arbitrary electron concentrations. This approach allows the quantitative modeling of thermodynamic defect equilibria in topological semimetals and is used to predict how Cd3As2 growth conditions affect the position of EF relative to the Dirac point.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 2221845
• Report Number(s): NREL/PR-5K00-85538; MainId:86311; UUID:cd2ad197-107b-444a-8857-17db018e4326; MainAdminID:71084
• Country of Publication: United States
• Language: English

Related Subjects

CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
defect equilibria
electronic structure
topological semimetal