A 17 GHz Molecular Rectifier

TL;DR

This paper reports the first demonstration of molecular diodes functioning at frequencies up to 17.8 GHz, showing significant potential for high-frequency molecular electronics and scaling down electronic components.

Contribution

It introduces a large array of molecular diodes operating at gigahertz frequencies, with a high rectification ratio and extrapolated cut-off frequency of 520 GHz, surpassing previous low-frequency molecular devices.

Findings

Molecular diodes operate up to 17.8 GHz.

Current density is several orders of magnitude higher than micrometer-scale devices.

Extrapolated cut-off frequency is 520 GHz.

Abstract

Molecular electronics originally proposed that small molecules sandwiched between electrodes would accomplish electronic functions and enable to reach ultimate scaling. However, so far, functional molecular devices have been only demonstrated at low frequency. Here, we demonstrate molecular diodes operating up to 17.8 GHz. DC (direct current) and RF (radio frequency) properties were simultaneously measured on a large array of molecular junctions composed of gold nanocrystal electrodes, ferrocenyl undecanethiol molecules, and the tip of an interferometric scanning microwave microscope. The present nanometer-scale molecular diodes offer a current density increase by several orders of magnitude compared to that of micrometer-scale molecular diodes, allowing RF operation. The measured S11 parameters show a diode rectification ratio of 12 dB which is linked to the rectification behavior of the DC conductance. From the RF measurements, we extrapolate a cut-off frequency of 520 GHz. A comparison with the silicon RFSchottky diodes architecture suggests that the RF-molecular diodes are extremely attractive for scaling and high-frequency operation.