The effect of hydrogen adsorption on the properties of undoped and Cu-doped ZnO(10(1)over-bar0) surfaces: A first-principles study

The effect of hydrogen adsorption on the electronic structure and properties of clean and Cu-doped ZnO(10 (1) over bar0) non polar surface was investigated using the first principles method. We found that the Cu-doped surface is more stable than the undoped one, and that high Cu solubility can be achieved in ZnO under O-rich condition with the use of metallic Cu as a Cu doping source. On the other hand, the obtained results show that hydrogen adsorption is more favored on Cu-doped-ZnO(10(1)over bar>0) surface than onto the clean surface, and this make Cu-doped ZnO surface and nanostructures more efficient for atomic H sensing applications than clean ZnO surface. We have also examined the effect of H adsorption on the surface work function of both clean and Cu-doped surfaces. We found that the adsorption of hydrogen molecule increases the work function of both surfaces, while, the adsorption of atomic hydrogen decreases significantly the surface work function. (C) 2015 Elsevier Ltd. All rights reserved.