Abstract. In this work, photoluminescence spectra of lightly doped SiC crystals with ingrown original defects are reported. , N D 110 18 cm -3 were investigated. The analysis of absorption, excitation and low temperature photoluminescence spectra suggests formation of a new micro-phase during the growth process and appearance of the deep-level (DL) spectra. The complex spectra of the crystals can be decomposed into the so-called DL i (i = 1, 2, 3, 4) spectra. The appearance of the DL i spectrum is associated with formation of new nano-phases. Data of photoluminescence, excitation and absorption spectra show the uniformity of different DL i spectra. Structurally, the general complexity of the DL i spectra correlated with the degree of disorder of the crystal and was connected with onedimensional disorder, the same as in the case of the stacking fault (SF i ) spectra. The DL i spectra differ from SF i spectra and have other principles of construction and behavior. The DL i spectra are placed on a broad donor-acceptor pairs emission band in crystals with higher concentrations of non-compensated impurities. The excitation spectra for the DL i and SF i spectra coincide and indicate formation of nanostructures 14H 1 4334, 10H 2 55, 14H 2 77, 8H44.