Geometry dependent current-voltage characteristics of ZnO nanostructures: A combined nonequilibrium Green's function and density functional theory study

摘要

Current-voltage (I-V) characteristics of different ZnO nanostructures were studied using a combined nonequilibrium Green's function and density functional theory techniques with the two-probe model. It was found that I-V characteristics of ZnO nanostructures depend strongly on their geometry. For wurtzite ZnO nanowires, currents decrease with increasing lengths under the same applied voltage conditions. The I-V characteristics are similar for single-walled ZnO nanotubes and triangular cross section ZnO nanowires but they are different from I-V characteristics of hexagonal cross section ZnO nanowires. Finally, our results are discussed in the context of calculated transmission spectra and densities of states.