Undoped and B-doped SiC layers were grown onto hexagonal SiC(00•1) substrates by means of solid-source molecular-beam epitaxy. Hexagonal 4H- and 6H-SiC layers were grown homoepitaxially, via step-controlled epitaxy, whereas cubic 3C-SiC was grown pseudomorphically via nucleation and subsequent step flow. The low-temperature photoluminescence spectra exhibited only the well-known emission lines of the so-called D1 center. The growth conditions, line-shape and line-shift were interpreted in terms of bound-exciton recombination at a native-defect complex which contained a Si vacancy.

On the Nature of the D1-Defect Centre in SiC: a Photoluminescence Study of Layers Grown by Solid-Source Molecular-Beam Epitaxy. A.Fissel, W.Richter, J.Furthmüller, F.Bechstedt: Applied Physics Letters, 2001, 78[17], 2512-4