Photoemission and density of valence states of the II–VI compounds. I. ZnTe, CdSe, CdTe, HgSe, and HgTe

Abstract

Abstract The density of valence states of the II–VI compounds ZnTe, CdSe, CdTe, HgSe, and HgTe have been determined with far uv ( h v = 21.2 and 40.8 eV) photoemission (UPS). Although the upper portions of the valence bands are found to have shapes in qualitative agreement with theory, they are consistently 1 to 2 eV wider than predicted. With the high resolution obtainable in uv photoemission, the shapes of the d‐bands of the cation can be resolved to permit an accurate determination of their positions relative to the top of the valence band and their spin‐orbit splittings. The “apparent” spin‐orbit splittings of the uppermost d‐orbitals of Zn and Cd are found to be 50% larger in the metallic form then in the compounds.