Interface formation of CuInSe2 (112) and ZnO deposited by atomic layer deposition

Interfaces of epitaxial CuInSe2 (112) surfaces to ZnO have been prepared by Atomic Layer Deposition (ALD) and are analyzed in situ by photoelectron spectroscopy at BESSY. LEED data show a (0001) oriented ZnO film for thicker films despite the large lattice mismatch. In contrast to results obtained from ZnO-MOMBE (Metal-Organic Molecular Beam Epitaxy) preparation where an inherent ZnSe interface layer of 2 nm is formed, for ALD a ZnIn2Se4 interface layer is observed which is introducing a different band alignment as in the MOMBE case. - Highlights: ► Interfacial behavior of CuInSe2 to ALD deposited ZnO investigated in situ by photoemission and LEED. ► In situ determined band alignment. ► Observation of a reacted interfacial layer of ZnIn2Se4. ► Application of synchrotron radiation to observe the substrate and overlayer signals with the same kinetic energy