Optical identification and electronic configuration of tungsten in 4H- and 6H-SiC

Abstract: Several optically observed deep level defects in SiC are still unidentified and little is published on their behavior. One of the commonly observed deep level defects in semi-insulating SiC is UD-1. This report suggests that UD-1 is Tungsten related, based on a doping study and previously reported deep level transient spectroscopy data, as well as photo-induced absorption measurements. The electronic levels involved in the optical transitions of UD-1 are also deduced. The transitions observed in the photoluminescence of UD-1 are from a Γ4 C3v, to two different final states, which transform according to Γ5 C3v⊕Γ6 C3v and Γ4 C3v, respectively. [Copyright &y& Elsevier]