The DNA of molecular electronics: nanoscale rectifiers

April 05, 2016 // By Julien Happich
Researchers from the University of Georgia and Ben-Gurion University of the Negev (BGU) have joined their efforts to develop what they believe to be the world's smallest diode, in fact the size of a single molecule.

The study published in Nature Chemistry under the title "Molecular rectifier composed of DNA with high rectification ratio enabled by intercalation" details how the Israeli and American researchers leveraged the predictability, diversity and programmability of DNA to design their first single molecule electronic device.

They constructed a DNA-based molecular rectifier by site-specific intercalation of small molecules (coralyne) into a custom-designed 11-base-pair DNA duplex.

Measuring current–voltage curves of the DNA–coralyne molecular junction exhibited unexpectedly large rectification with a rectification ratio of about 15 at 1.1 V, a counter-intuitive finding considering the seemingly symmetrical molecular structure of the junction.

The researchers wrote a non-equilibrium Green's function-based model, parameterized by density functional theory calculations, revealing that the coralyne-induced spatial asymmetry in the electron state distribution caused the observed rectification.

"Creating and characterizing the world's smallest diode is a significant milestone in the development of molecular electronic devices," stated Dr. Yoni Dubi, a researcher in the BGU Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology. "It gives us new insights into the electronic transport mechanism."

The nanoscale diode thus obtained operates like a valve to facilitate electronic current flow in one direction. A collection of these nanoscale diodes, or molecules, has properties that resemble traditional electronic components such as a wire, transistor or rectifier.

The researchers see molecular electronics as a possible route to overcome Moore's Law beyond the limits of conventional silicon-based semiconductors.

Visit the University of Georgia at http://uga.edu/

Visit the Ben Gurion University of the Negev at http://in.bgu.ac.il/en

 

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