TABLE OF CONTENTS The wide band gap in SiC has made it possible to fabricate light-emitting devices for the essentially entire visible spectrum. The same mechanism of radiative recombination (the same technique for fabrication of a light-emitting diode) corresponding to different energies for the emission peak in different polytypes; i.e., compared to 6H-SiC, the position of the electroluminescence peak shifts to shorter wavelengths (in the case of a wider gap polytype) or to longer wavelengths (in the case of a narrower gap polytype) by an amount roughly equal to the difference between the band gaps of the given polytype and 6H- SiC (Fig. 6). As can be seen from this figure, the energy of the emission peaks depends linearly on the width of the band gap. The intercept formed by extrapolating these curves to zero hv max can be used to roughly estimate the ionization energy of the recombination center [the sum of the energies of two centers, in the case of a donor-acceptor recombination (DAR)]
The EL spectra of 4H and 6H p-n structures doped with various impurities were analyzed in detail in ref.198. It was concluded that, in 6H and 4H SiC, the
