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Thermally stable carbon-related centers in 6H-SiC: photoluminescence spectra and microscopic models

Alexander Mattausch·Michel Bockstedte·Oleg Pankratov·John W. Steeds·Suzanne Furkert·Jonathan M. Hayes·Wayne Sullivan·Nick G. Wright
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Abstract

Recent ab initio calculations [Mattausch et al., Phys. Rev. B 70, 235211 (2004)] of carbon clusters in SiC reveal a possible connection between the tricarbon antisite (C_3)_Si and the U photoluminescence center in 6H-SiC [Evans et al., Phys. Rev. B 66, 35204 (2002)]. Yet, some of the predicted vibrational modes were not observed experimentally. Here we report experiments which indeed confirm the existence of a low-energy mode for the U-center (as well as for the HT3- and HT4-centers with spectral details similar to the U-center). We calculated the isotope splitting for the (C_3)_Si-defect and found near-perfect agreement with our data. In addition, we discuss the carbon di-interstitial (C_2)_Hex as a model for the Z- and HT5-centers. The isotope splitting is also well reproduced, but the absolute values of the local mode energies show a discrepancy of about 10 meV.

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Alexander Mattausch, Michel Bockstedte, Oleg Pankratov, John W. Steeds, Suzanne Furkert, Jonathan M. Hayes, Wayne Sullivan, Nick G. Wright. 2006-03-23. Thermally stable carbon-related centers in 6H-SiC: photoluminescence spectra and microscopic models. https://doi.org/10.1103/physrevb.73.161201

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