In IN, EL characterization it was concluded that during the growth on n-type 6H-SiC substrate of 3C-SiC layer the not intentionally doped regions of p-type conductivity formed. It thus appears that two types of pn structures are being formed identified by the polarity of voltage applied to Ni contact on the surface of the epitaxial layer and displaying different spectra of injection EL. In the EL spectra of the first structure type a peak at hnu(max) = 2.3 eV is present which, similar to the peak due to free exciton annihilation in 3C-SiC. In the EL spectra of the second structure type two peaks are observed of the same origin as the peaks identified in 6H-SiC pn structures and one more, longer wavelength peak at hnu(max) between 2.35 and 2.5 eV. TEM revolved that the intermediate layer belongs to 6H polytype. According to EBIC characterization the intermediate layer in studied sample was p-type conductivity.