Theoretical characterization of NV-like defects in 4H-SiC using ADAQ with SCAN and r2SCAN meta-GGA functionals
Ghulam Abbas, Oscar Bulancea-Lindvall, Joel Davidsson, Rickard Armiento, Igor A. Abrikosov
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.