Higher Absorption Edges in Cubic SiC

In addition to the known indirect absorption edge of cubic SiC at 2.39 eV, measurements of light absorption in thin samples reveal indirect edges at 3.55 and 4.2 eV. Comparisons are made with calculated band separations. The absorption coefficient at 5 eV is 2.4×${10}^4$ ${\mathrm{cm}}^{-1\mathrm{}}$. There is no absorption edge near 4.6 eV, where some reflectivity measurements have suggested one. The first direct transition appears to be near 6 eV.