A previously unreported photoluminescence spectrum observed in certain 4H SiC bipolar diodes was found after extended forward voltage operation. This emission was attributed to exciton recombination at local potential fluctuations, caused by stacking faults which were created during operation of the diodes.

Luminescence from Stacking Faults in 4H SiC. S.G.Sridhara, F.H.C.Carlsson, J.P.Bergman, E.Janzén: Applied Physics Letters, 2001, 79[24], 3944-6