Development of Single-Molecule Diode Revolutionizes Nanotechnology

Development of Single-Molecule Diode Revolutionizes Nanotechnology

A paper published on May 25 in Nature Nanotechnology titled ‘Single-Molecule Diodes with High On-Off Ratios through Environmental Control’ reports the first ever attempt for the development of single-molecule diode that perform 50 times better than all the previous designs.

A team of Columbia Engineering researchers under the guidance of an Indian-American associate professor of applied physics at Columbia Engineering, Latha Venkataraman have designed this single-molecule electronic device which would revolutionize nanoscale devices.

Venkataraman proudly stated that the new device represents the ultimate in functional miniaturisation that can be achieved for an electronic device. He added that constructing a device where the active elements are only a single molecule has long been a tantalizing dream in nanoscience.

Further, Venkataraman explained enthusiastically, “It’s amazing to be able to design a molecular circuit, using concepts from chemistry and physics, and have it do something functional. It is truly a triumph to be able to create something that you will never be able to physically see and that behaves as intended”.

In this study, the researchers have used asymmetric molecular design in order to develop a single-molecule diode. Brian Capozzi, PhD student working with Venkataraman and lead author of the paper stated that while such asymmetric molecules do indeed display some diode-like properties, they are not effective as they typically suffered from very low current flow in both ‘on’ and ‘off’ directions and even the ratio of current flow is very low.

In order to overcome the issues, Venkataraman and her colleague rather created an environmental asymmetry through a simple method of surrounding the active molecule with an ionic solution and used gold metal electrodes of different sizes to contact the molecule. This simple new technique can be easily applied to all nanoscale devices of all types, including those that are made with graphene electrodes.