Theoretical study of ZnO(1 0 0) and M/ZnO(1 0 0) (M = Cu, Ag and Au) surfaces with DFT approach

Density functional calculations with the plane-wave pseudopotential method have been carried out in order to determine the geometric and electronic structure of ZnO(1 0 1 ¯ 0) and M/ZnO(1 0 1 ¯ 0) (M = Cu, Ag and Au). Surface formation energies of the ZnO(1 0 1 ¯ 0) surfaces were calculated. Spilling effect and Friedel oscillation effect were observed for the ZnO(1 0 1 ¯ 0) surface. Cu and Ag are energetically favorable to connect with O atoms while Au is energetically favorable to connect with Zn atom on the surface at full coverage. Binding energies and vibrational frequencies were analyzed. The results were compared with previous theoretical studies and available experiments.