X-Ray Absorption Spectroscopy Study of Copper Doped ZnO Thin Films

Abstract

X‐ray absorption spectroscopy technique is used to study copper‐doped ZnO thin films, prepared by pulsed‐laser deposition. The samples with various doping levels are examined. It is found that the samples contain metallic clusters with the sizes ⩽ 2 nm as well as Cu1+ and Cu2+ states. The Cu1+ states exist as stable oxide clusters, while the Cu2+ ones participate in the ZnO lattice some of which may be pertaining to the surfaces of the Cu clusters as well. The copper clusters of ∼1 nm are unstable and fragment under monochromatic x‐ray beam illumination.