ATOM AND BOND CENTERED LOCALIZED VALENCE-BAND STATES IN CD0.5ZN0.5TE ALLOYS

Angle-resolved valence-band photoemission spectroscopy is used to analyze the local electronic structure in Cd0.5Zn0.5Te(100) alloy films. Localized alloy valence-band states may be divided into two categories: (1) Atom centered states associated with Cd 4d and Zn 3d core-like states, and (2) bond centered states associated with the X6 critical point of the split-off band. While the atom centered states show distinct emission and no intermixing between Cd 4d and Zn 3d bands near the GAMMA point, bond centered X6 states are mixed but split by approximately 0.4 eV. We discuss our experimental results within the framework of Wei and Zungers structural model, and show how far experimental evidence corroborates their theory.