Water adsorption on ZnO(101̄0): The role of intrinsic defects

Density functional theory (DFT) calculations have been performed to investigate the interaction of water molecules with bare and defective ${\rm ZnO}(10{\overline 1}0) $ surfaces. We show that at high coverages water molecules avoid adsorption close to defect sites, whereas at low coverages adsorption on defective surfaces show a similar adsorption pattern to those adsorbed on the defect-free surface, adsorbing in a molecular fashion. Finally we show that the electronic structure of the defective non-polar surface is not much affected by the adsorption of water, with exception of the O-defect surfaces