3C-SiC epitaxial layers with a thickness of up to 100 μm and area of ~0.3-0.5 cm2 have been grown by sublimation epitaxy on hexagonal (6H-SiC) substrates at a maximum growth rate of about 200 μm per hour. The epilayers obtained are of n-type (Nd-Na ~ 1017 -1018 cm-3). According to X-ray data, the epitaxial layers are composed of the 3C-SiC polytype, without inclusions of other polytypes. The donor-acceptor (Al-N) recombination band with hνmax ~ 2.12 eV predominates in the photoluminescence (PL) spectrum. A detailed analysis of a PL spectrum measured at 6 K is presented. A conclusion is made that the epitaxial layers can be used as substrates for electronic devices based on 3C-SiC.