Far-infrared study of alloying in the HgTe-CdTe superlattice

Abstract
The far‐infrared reflectivity spectra of three HgTe‐CdTe superlattices from two sources [HgTe/CdTe thicknesses (Å/Å): 64/26, 7/35, 32/57] have been measured at 300, 77, and 6 K. Analysis of transverse optical phonon structure between 80 and 180 cm1 with different alloying models shows that the first of these superlattices contains HgTe and CdTe with no evidence of significant mixing, whereas the others contain HgTe and homogeneous Hg1−xCdxTe. An earlier study of the HgTe‐CdTe band gap also indicated homogeneous alloying. The reflectivity data were analyzed with a superlattice dielectric function which is shown to be valid in the far infrared.