A photoelectron spectroscopy study of the electronic structure evolution in CuInSe2-related compounds at changing copper content

Abstract

Evolution of the valence-band structure at gradually increasing copper content has been analysed by x-ray photoelectron spectroscopy (XPS) in In 2Se 3, CuIn 5Se 8, CuIn 3Se 5, and CuInSe 2 single crystals. A comparison of these spectra with calculated total and angular-momentum resolved density-of-states (DOS) revealed the main trends of this evolution. The formation of the theoretically predicted gap between the bonding and non-bonding states has been observed in both experimental XPS spectra and theoretical DOS. © 2012 American Institute of Physics.