Carbon antisite clusters in SiC: a possible pathway to the DII center

Original · EN

The photoluminescence center DII is a persistent intrinsic defect which is common in all SiC polytypes. Its fingerprints are the characteristic phonon replicas in luminescence spectra. We perform ab-initio calculations of vibrational spectra for various defect complexes and find that carbon antisite clusters exhibit vibrational modes in the frequency range of the DII spectrum. The clusters possess very high binding energies which guarantee their thermal stability--a known feature of the DII center. The di-carbon antisite (C₂)Si (two carbon atoms sharing a silicon site) is an important building block of these clusters.