Deep centers and electroluminescence in 4HSiC diodes with a p-type base region

We have performed electrical and optical measurements to characterize the processes of radiative recombination of carriers for 4H-SiC p-n+ junctions. We have detected three levels in the band gap, using capacitance and current deep-level transient spectroscopy, which are responsible for the bands observed in the electroluminescence spectra. We assume that the HK1 center with an activation energy of Ev + 0.229 eV and a hole capture cross-section of 8 × 10−13 (300/T)3 is related to the Al acceptor level.