Thermal injection current in 3C-SiC pn structures

The Results are presented of a systematic investigation of the current–voltage (I–V) characteristics of forward biased pn structures prepared by Al diffusion into platelets of bulk cubic silicon carbide (3C-SiC). Structures selected for detailed investigation had I(V) dependence of the type J=J0 exp(qV/nkT), where J0=J0* exp(−Ea/kT) and parameter n close to 2. The green electroluminescence in such structures was most intensive and uniform and could be observed at the lowest currents. The room temperature pre-exponential factor in the expression for current density J0 in these structures is in the range 10−18–10−17 A cm−2, the activation energy Ea is about 1.2 eV. A model of carrier recombination and generation in the space charge region of a pn junction through a deep level is used. The results of this study compare with those of earlier investigations. It can be stated that in 3C-SiC pn structures the thermal injection current due to carrier recombination in the space charge region has been observed for the first time.