Pseudo-Equilibrium Theory for Extrinsic Doping Control of the Topological Semimetal Cd3As2

Journal Article · Tue Nov 18 00:00:00 EST 2025 · npj Computational Materials

DOI:https://doi.org/10.1038/s41524-025-01841-w· OSTI ID:3014885

Brooks, Chase ^[1]; Lany, Stephan ^[2]

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1. University of Colorado Boulder
2. National Laboratory of the Rockies, Golden, CO (United States)

The standard approach for predicting defect equilibria from first principles assumes that the solid-state system is initially in a thermodynamic equilibrium with the external atomic reservoirs. This “growth step” is then often followed by a temperature quench in a “pseudo-equilibrium” in which some or all defect concentrations are frozen in until only the Fermi level EF remains to be equilibrated. However, this protocol does not account for the possibility of site exchanges which can create important defect redistributions as long as short-range defect migration is kinetically permissible. To model this redistribution, we developed an approach to solve for the non-equilibrium chemical potentials as a function of temperature while maintaining the overall defect stoichiometry. We then apply this approach to the Dirac semimetal Cd3As2 to model extrinsic doping with group 1/11 and 14 elements. Undoped Cd3As2 exhibits an undesirable mismatch between EF and the Dirac point. This unintentional electron doping originates from intrinsic defects and is difficult to overcome through adjustment of synthesis conditions alone. Employing our pseudo-equilibrium modeling, we identify extrinsic doping strategies for realizing doping-balanced Cd3As2 at the relatively low temperatures accessible in thin-film growth of this material.

• Research Organization: National Laboratory of the Rockies (NLR), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 3014885
• Report Number(s): NLR/JA-5K00-95065
• Journal Information: npj Computational Materials, Journal Name: npj Computational Materials Vol. 11
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
defect theory
first principles calculations
topological semimetal