Theoretical characterization of NV-like defects in 4H-SiC using ADAQ with SCAN and r2SCAN meta-GGA functionals

Abstract

Kohn-Sham density functional theory is widely used for screening color centers in semiconductors. While the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation functional is efficient, its accuracy in describing defects is often not sufficient. The Heyd-Scuseria-Ernzerhof (HSE) functional is more accurate but computationally expensive, making it impractical for large-scale screening. This study evaluates the strongly constrained and appropriately normed (SCAN) family of meta-GGA functionals as potential alternatives to PBE for characterizing NV-like color centers in 4H-SiC using the Automatic Defect Analysis and Qualification (ADAQ) framework. We examine nitrogen, oxygen, fluorine, sulfur, and chlorine vacancies in 4H-SiC, focusing on applications in quantum technology. Our results show that SCAN and r2SCAN achieve a greater accuracy than PBE, approaching HSE's precision at a lower computational cost. This suggests that the SCAN family offers a practical improvement for screening new color centers, with computational demands similar to PBE.