Cu depletion at the CuInSe2 surface

Abstract

The chemical composition of the (112)B surface of epitaxial ${\mathrm{CuInSe}}_2$ thin films is investigated by angle resolved x-ray photoelectron spectroscopy. Results show that a severe Cu depletion exists in the top 1–2 atomic layers. No bulk second phase is found at the surface. The source of this depletion and its relation to the Cd doping at the $\mathrm{CdS}/{\mathrm{CuInSe}}_2$ interface are discussed.