Scientists at Tokyo Institute of Technology designed a new type of molecular wire doped with organometallic ruthenium to achieve unprecedentedly higher conductance than earlier molecular wires. The origin of high conductance in these wires is fundamentally different from similar molecular devices and suggests a potential strategy for developing highly conducting "doped" molecular wires.
Since their conception, researchers have tried to shrink electronic devices to unprecedented sizes, even to the point of fabricating them from a few molecules.
Molecular wires are one of the building blocks of such minuscule contraptions, and many researchers have been developing strategies to synthesize highly conductive, stable wires from carefully designed molecules.
A team of researchers from Tokyo Institute of Technology, including Yuya Tanaka, designed a novel molecular wire in the form of a metal electrode-molecule-metal electrode (MMM) junction including a polyyne, an organic chain-like molecule, "doped" with a ruthenium-based unit Ru(dppe)2.
The proposed design, featured in the cover of the Journal of the American Chemical Society, is based on engineering the energy levels of the conducting orbitals of the atoms of the wire, considering the characteristics of gold electrodes.
Using scanning tunneling microscopy, the team confirmed that the conductance of these molecular wires was equal to or higher than those of previously reported organic molecular wires, including similar wires "doped" with iron units. Motivated by these results, the researchers then went on to investigate the origin of the proposed wire's superior conductance.
They found that the observed conducting properties were fundamentally different from previously reported similar MMM junctions and were derived from orbital splitting. In other words, orbital splitting induces changes in the original electron orbitals of the atoms to define a new "hybrid" orbital facilitating electron transfer between the metal electrodes and the wire molecules. According to Tanaka, "such orbital splitting behavior has rarely been reported for any other MMM junction".
Since a narrow gap between the highest (HOMO) and lowest (LUMO) occupied molecular orbitals is a crucial factor for enhancing conductance of molecular wires, the proposed synthesis protocol adopts a new technique to exploit this knowledge, as Tanaka adds "The present study reveals a new strategy to realize molecular wires with an extremely narrow HOMO?LUMO gap via MMM junction formation."
This explanation for the fundamentally different conducting properties of the proposed wires facilitate the strategic development of novel molecular components, which could be the building blocks of future minuscule electronic devices.
Emiko Kawaguchi | EurekAlert!
Epoxy compound gets a graphene bump
14.11.2018 | Rice University
Automated adhesive film placement and stringer integration for aircraft manufacture
15.11.2018 | Fraunhofer IFAM
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences