Electron transport through Al-ZnO-Al: an {\it ab initio} calculation

TL;DR

This paper investigates electron transport in Al-ZnO-Al nano-junctions using ab initio methods, revealing rectifying behavior, negative differential resistance, and potential for device applications based on electrochemical capacitance features.

Contribution

It provides a detailed ab initio analysis of electron transport in Al-ZnO-Al nano-contacts, highlighting the roles of interface chemistry and bias voltage effects.

Findings

Rectifying current-voltage characteristics observed.

Negative differential resistance at negative bias.

Electrochemical capacitance shows three plateaus.

Abstract

The electron transport properties of ZnO nano-wires coupled by two aluminium electrodes were studied by {\it ab initio} method based on non-equilibrium 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.