An intense photoluminescence spectrum, with no-phonon lines which were due to the 3T2  3A2 transition of isolated VGa3+, was found for material which was co-doped with V and S. In addition, a new spectrum with no-phonon lines at 5641.3/cm (line C) and 5655.2/cm (line D) was found. Line C split into 2 components under an uniaxial stress which was directed along <111> and <110>, but did not split when the stress was along <100>. This indicated that C and D were transitions of a V3+ center, with trigonal symmetry, that was probably caused by a VGa-SP pair defect.

S.Steck, G.Rückert, K.Thonke, W.Ulrici, R.Sauer: Materials Science Forum, 1995, 196-201, 731-6