Avalanche Breakdown Electroluminescence in Silicon Carbide Light Emitting Diodes

Room temperature electroluminescence was obtained from silicon carbide diodes. The spectrum was recorded in the 1.1 to 3.2 eV energy range. In forward bias, the intensity maximum occurs at 2.64 eV and in avalanche breakdown at 2.2 eV. The lifetime of the latter is 179 ns. In forward bias, the lifetime was previously measured to be 2.3 mus. It is concluded that, in SIG, forward and reverse bias emissions have different origins, and the reverse bias emission cannot be band to band. The SiC data supports the view that the mechanisms of avalanche breakdown electroluminescence are bremsstrahlung and intraband, involving hot carriers.