Fundamental Reflectivity and Band Structure of ZnTe, CdTe, and HgTe

The fundamental reflectivity of ZnTe, CdTe, and HgTe has been measured over the energy range 1.0-25 eV at room temperature and 1.0-6.5 eV at 77^∘{}K. Corners and maxima in the reflectivity are identified with interband transitions at the symmetry points Γ, L, and X and in the [111] direction inside the Bril-louin zone. At about 12 eV the reflection spectrum of these and other II-VI compounds shows structure which has been assigned to transitions from d-electron levels in the metal to the conduction band. The systematics of the band structure of zincblende-type compounds is discussed. Several rules are given for calculating effective masses in these and related materials.