Electronic and optical properties of vanadium doped silicon carbide crystals grown by the sublimation sandwich method

Cathodoluminescence-mapping experiments of n- and p-type 6H SiC intentionally doped with vanadium (V) show a local anti-correlation of the V4+ related IR-luminescence and the near bandedge donor-acceptor pair luminescence (N --> Al). This fact indicates, that V acts as minority carrier lifetime determining impurity. The suppression of the V4+ luminescence near crystallographic defects is discussed under the possible mechanism of V precipitate formation. The binding-energy of the V-4+/5+ donor level is determined to E(V) + 1.57 +/- 0.05 eV by photoluminescence excitation measurements.