Electron transport through Al–ZnO–Al: an ab initio calculation

Abstract

The electron transport properties of ZnO nanowires coupled by two aluminum electrodes were studied by ab initio method based on nonequilibrium Green’s function approach and density functional theory. A clearly rectifying current-voltage characteristics was observed. It was found that the contact interfaces between Al–O and Al–Zn play important roles in the charge transport at low bias voltage and give very asymmetric I-V characteristics. When the bias voltage increases, the negative differential resistance occurs at negative bias voltage. The charge accumulation was calculated and its behavior was found to be well correlated with the I-V characteristics. We have also calculated the electrochemical capacitance which exhibits three plateaus at different bias voltages which may have potential device application.