Designing the rectification behavior of molecular diodes

Thanks to major advances in chemical and fabrication processes, various electronic devices based on single molecules have been demonstrated. On the theoretical level, many attempts have been made to provide a clear view of the charge transport mechanism through molecules. However, the overall picture is not yet complete. In this study, we show that the rectification of a molecular device can be controlled by enforcing the potential drop profile along the molecule. The insertion of a resistive molecular path near the metallic electrode(s) can drastically alter the rectification behavior. Our observation paves the way for a better control of molecular devices.