Density functional theory calculation of the properties of carbon vacancy defects in silicon carbide

• Published in: Nanotechnology and Precision Engineering Vol. 3; no. 4; pp. 211 - 217
• Main Authors: Wang, Xiuhong, Zhao, Junlei, Xu, Zongwei, Djurabekova, Flyura, Rommel, Mathias, Song, Ying, Fang, Fengzhou
• Format: Journal Article
• Language: English
• Published: State Key Laboratory of Precision Measuring Technology&Instruments,Centre of MicroNano Manufacturing Technology,Tianjin University,Tianjin 300072,China 01.12.2020; Department of Electrical and Electronic Engineering,Southern University of Science and Technology,Shenzhen 518055,China%State Key Laboratory of Precision Measuring Technology&Instruments,Centre of MicroNano Manufacturing Technology,Tianjin University,Tianjin 300072,China%Department of Physics and Helsinki Institute of Physics,University of Helsinki,P.O. Box 43,FI-00014 Helsinki,Finland%Fraunhofer Institute for Integrated Systems and Device Technology IISB,Schottkystrasse 10,91058 Erlangen,Germany; Department of Physics and Helsinki Institute of Physics,University of Helsinki,P.O. Box 43,FI-00014 Helsinki,Finland%Department of Physics and Helsinki Institute of Physics,University of Helsinki,P.O. Box 43,FI-00014 Helsinki,Finland; AIP Publishing LLC
• Subjects: Carbon vacancy; Density functional theory; Silicon carbide; Carbon vacancy; Density functional theory; Silicon carbide
• ISSN: 1672-6030; 2589-5540; 2589-5540
• DOI: 10.1016/j.npe.2020.11.002

As a promising material for quantum technology, silicon carbide (SiC) has attracted great interest in materials science. Carbon vacancy is a dominant defect in 4H-SiC. Thus, understanding the properties of this defect is critical to its application, and the atomic and electronic structures of the defects needs to be identified. In this study, density functional theory was used to characterize the carbon vacancy defects in hexagonal (h) and cubic (k) lattice sites. The zero-phonon line energies, hyperfine tensors, and formation energies of carbon vacancies with different charge states (2−, −, 0,+ and 2+) in different supercells (72, 128, 400 and 576 atoms) were calculated using standard Perdew–Burke–Ernzerhof and Heyd–Scuseria–Ernzerhof methods. Results show that the zero-phonon line energies of carbon vacancy defects are much lower than those of divacancy defects, indicating that the former is more likely to reach the excited state than the latter. The hyperfine tensors of VC+(h) and VC+(k) were calculated. Comparison of the calculated hyperfine tensor with the experimental results indicates the existence of carbon vacancies in SiC lattice. The calculation of formation energy shows that the most stable carbon vacancy defects in the material are VC2+(k), VC+(k), VC(k), VC−(k) and VC2−(k) as the electronic chemical potential increases.