Deep level optical spectroscopy investigations were taken on high-quality n-type 4H-, 6H- and 3C-SiC epilayers grown by the chemical vapor deposition and, for comparison, also on n-type 4H-SiC bulk material grown by the sublimation technique. Midgap levels were determined at E-C-Edegrees(MG4A/B) = 1.70/1.33eV in 4H-SiC, at E-C-Edegrees(MG6) = 1.55eV in 6H-SiC and at E-C-Edegrees(MG3) = 1.00eV in 3C-SiC. These levels are energetically aligned in the bandgap of the investigated SiC polytypes. Time-resolved photoluminescence measurements were performed on the identical 4H-SiC epilayer and bulk crystal as used for the electrical characterization; the corresponding decay times of the photoluminescence are 180ns and 15ns. It is suggested that the observed midgap defects are suitable candidates for lifetime killers.