Polarized-light photoemission studies of wurtzite CdS

Abstract

Polarized-light vacuum ultraviolet photoemission measurements have been made on vacuum-cleaved wurtzite CdS. A high-energy shoulder associated with an optical transition permitted for only $\overrightarrow{\mathrm{E}}\parallel \overrightarrow{\mathrm{c}}$ has been observed and related to structure in the reflectivity between 11 and 12 eV. Observed polarization dependence of the trailing edge indicates that the photoelectric threshold is determined by the band structure and density of states as well as the electron escape probability. It is indicated that many features of the energy distribution curves are not explained by a simple qualitative comparison to an empirical pseudopotential band structure.