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

Abstract

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\ifmmode^\circ\else\textdegree\fi{}K. Corners and maxima in the reflectivity are identified with interband transitions at the symmetry points $\ensuremath{\Gamma}$, $L$, 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.