and thus the Fermi energy level of Au is higher than that of ZnO. In order to align the Fermi energy level at
equilibrium, electrons flow from Au to ZnO after the deposition of Au NPs on ZnO nanobelts. This behavior will cause the
upward shift of the band edge for ZnO and further leads to its band bending at the interface. As a consequence, ohmic
contact was formed between ZnO and Au, the energy band structure of which is shown in Fig. 10.