Ultraviolet Reflectivity Spectra ofCdS1−xSexSingle Crystals

The fundamental reflectivity of single-crystal platelets of $\mathrm{Cd}{\mathrm{S}}_{1-x}{\mathrm{Se}}_x$ has been measured at 90°K with linearly polarized light of wavelength longer than 1100 Å. Measurements were performed with the electric vector parallel and perpendicular to the $c$ axis of the crystal. The transitions $E_1(A_1, A_2, B)$, ${E_0}^{\prime }$, $F_1$, $E_2$, a shoulder on the low-energy side of $E_2$, and ${E_1}^{\prime }$ were followed across the composition range. The structure in the reflectivity curves is interpreted in terms of existing knowledge of the band structure of wurtzite materials.