Substrate effect on the structure and properties of Cu clusters supported on ZnO

To understand the interaction between the Cu clusters and the ZnO substrate, we performed density functional theory (DFT) calculations on the adsorptions of small copper clusters on the ZnO(100) surface. The PBE functional was used in the DFT calculations with a plane wave basis set. The structural changes of the Cu clusters upon adsorption on the ZnO surface were provided. Although a few different adsorption sites are available, a single Cu atom was found to be adsorbed on three positions on a ZnO(100) surface. The adsorption strength of a Cu dimer is increased with respect to the adsorption of a single Cu atom. In the adsorptions of tetramers, and pentamers, three-dimensional configurations of Cu clusters are more favorable than the planer.