Optical Studies of β‐SiC

Abstract

Abstract The results of a study to characterize samples of single crystals of β‐SiC grown by a modified Czochralski technique are given. The X‐ray diffraction patterns were indexed as a face‐centered cubic lattice whose parameter was a 0 = 4.357 Å and showed virtually no twinning. The absorption measurements in the region from 1.5 to 4.0 eV yielded an estimate for the band gap for the indirect transition as 2.60 eV which agree with that obtained from photoconductance experiments. In the region from 0.05 to 0.5 eV room temperature absorption measurements showed absorption bands which could be tentatively assigned as two‐phonon bands. Raman spectrum excited by the 6328 Å line of the HeNe laser showed two bands, one at 795 cm −1 taken as the transverse optical mode, and one at 995 cm −1 taken as the longitudinal mode.