We report an optical study of sinusoidally modulated ZnSeTe superlattices using spectroscopic ellipsometry. The pseudodielectric function 〈∈〉 = 〈∈1〉 + i〈∈2〉 was determined for the photon energy range 1.5-6.5 eV and critical point parameters were obtained by fitting model line shapes to numerically calculated second energy derivatives of 〈∈〉. As the degree of the compositional modulation of the superlattice increased, the energies of E1-R1 and E1 + Δ1 - R1 either decreased or increased depending on the superlattice period. We explain this behavior in terms of an interlayer coupling and quantum-confinement effect characteristic, respectively, for the two geometries.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)