Compositional Disorder and Interband Transitions in Pb sub 1-x Cd sub x S Alloys.

摘要

Optical absorption and thermoreflectance spectra are reported for the E1, E1 + Delta 1 doublet in Pb(1-x)Cd(x)S metastable epitaxial films (NaCl structure). The bowing parameter for E1 is approx. 1 eV or less, while for E1 + Delta 1 we find 4.1-4.8 eV. The latter is much larger than any value reported heretofore, and may be explained by the large fluctuation potential arising from atoms of different valence randomly occupying the metal sublattice. Differences between E1 and E1 + Delta 1 imply strong disorder-induced mixing of states which is concentration-dependent. (Author)