Optical Detection of Magnetic Resonance for an Effective-Mass-like Acceptor in6H-SiC

Optical detection of magnetic resonance is reported for the blue donor-acceptor pair luminescence in $6H$-SiC containing nitrogen and aluminum. The nitrogen donor resonance is isotropic, with $g=2.004\mathrm{}\pm 0.002$. Resonances for the aluminum acceptor in three inequivalent silicon lattice sites are detected with $g_{\parallel }=2.412\mathrm{}\pm 0.002, 2.400\pm 0.002, \mathrm{and} 2.325\pm 0.002$; and $g_{\perp }=0\mathrm{}$. This indicates an effective-mass-like character for the acceptor, but with reduced orbital contribution due to the localization. Evidence for corresponding reduction in the spin-orbit splitting is cited.