Strain-modulated transport properties of Cu/ZnO-nanobelt/Cu nanojunctions

The transport properties of Cu/ZnO-nanobelt/Cu nanostructures under uniaxial strains were studied using first-principles calculations, with emphasis on the interfacial contacts. The conductivity G is very sensitive to strain, and it decreases linearly when strain varied from compression to tension, and the piezoresistive gauge factors (GFs) of ZnO nanobelts in non-polarized direction are 5.66 and 4.29 for compressive (ϵ=−0.05) and tensile strain (ϵ=0.05), respectively. As shown in local density of states (LDOS), the number of carriers nearby the Fermi level decreased obviously when the strains changed from compression to tension, which could be used to explain the linearly decreased conductance. In terms of the transferred interfacial charge and potential profiles, the energy barriers between Cu and ZnO nanobelts could be reduced by strains. These results could help to understand the physics in the strain-induced metal/ZnO contacts and be used to modulate effectively the performances of ZnO nanodevices.