New deep acceptor in epitaxial cubic SiC

Abstract
We have investigated the temperature and excitation intensity dependence of photoluminescence (PL) spectra in several undoped and lightly Al-doped thin films of cubic SiC grown by chemical vapor deposition on Si substrates. The low-power PL spectra in all samples studied exhibit a deep donor-acceptor pair PL band which involves a previously undetected deep acceptor (EA=470 meV). The pervasive character of this deep acceptor suggests the possibility that it is at least partially responsible for the high compensation observed in undoped films of cubic SiC.