EPR and theoretical studies of negatively charged carbon vacancy in 4H-SiC
2005 (English)Article in journal (Refereed) Published
Carbon vacancies (VC) are typical intrinsic defects in silicon carbides (SiC) and so far have been observed only in the form of positively charged states in p -type or semi-insulating SiC. Here, we present electron- paramagnetic-resonance (EPR) and photoinduced EPR (photo-EPR) observations of their negatively charged state (VC-) in n -type 4H-SiC. This EPR center (called HEI1) is characterized by an electron spin of 1 2 in a Si-Si antibonding state of VC. First-principles calculations confirm that the HEI1 center arises from VC- at hexagonal sites. The HEI1 spectrum shows a transition between C1h and C3v symmetries due to a fast reorientation effect reflected in the nature of this defect. The photo-EPR data suggest that VC 2- is the dominant form of VC when the Fermi level lies 1.1 eV below the conduction band. © 2005 The American Physical Society.
Place, publisher, year, edition, pages
2005. Vol. 71, no 19
IdentifiersURN: urn:nbn:se:liu:diva-30705DOI: 10.1103/PhysRevB.71.193202Local ID: 16317OAI: oai:DiVA.org:liu-30705DiVA: diva2:251528