Revisiting point defects in cubic boron arsenide from first-principles calculations

Abstract

Cubic boron arsenide (c-BAs), known for its high carrier mobilities and exceptional thermal conductivity at room temperature, was successfully synthesized via chemical vapor transport. Using first-principles calculations, we revisit the electronic and thermodynamic properties of point defects in c-BAs. Acceptor defects such as V_B, B_As, and Si_As, as well as donor defects like As_B and Si_B are expected to dominate under both arsenic-rich and boron-rich conditions. Furthermore, acceptor defects exhibit lower formation energies than donor defects, indicating that c-BAs behaves as a p-type semiconductor, consistent with experimental observations. The V_B defect is predicted to be dynamically stable due to its high migration barrier. Additionally, the density of states of As_B reveals the presence of in-gap defect states, which could lead to the formation of multiple recombination centers. This work provides valuable insights into the defect physics of c-BAs and will support the development of device applications based on this material.