Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Understanding charge transfers in molecular electronics

Enrique del Barco’s work will contribute to advancing the understanding of quantum technologies.
Enrique del Barco’s work will contribute to advancing the understanding of quantum technologies.

Abstract:
An international research team, which includes University of Central Florida Professor Enrique del Barco and Christian A. Nijhuis of the National University of Singapore, has found a way to understand and manipulate the transition of charges in molecular junctions.

Understanding charge transfers in molecular electronics

Orlando, FL | Posted on March 30th, 2018

A molecular junction connects molecules to two metallic electrodes, such as gold. For electrons to flow through the junction they need to overcome a barrier. When temperature is increased, the electrons can jump over the barrier more easily.

Charge transfers dominate many chemical reactions, such as when iron rusts and turns brown. The iron loses electrons, causing rust. Iron is a metal, but the same applies to molecular reactions, known as electrochemistry. The science behind molecular charge transfer is well understood in the field of chemistry, and explained by the so-called Marcus Theory.

According to this theory, molecular reaction speeds can be tuned by increasing or decreasing temperature (known as Direct Marcus regime). However, under some circumstances, the reaction can be taken into the Inverted Marcus regime, where the reaction becomes insensitive to changes in temperature, and can jump without crossing a barrier.

Charge transfer processes are also becoming increasingly important in the emerging field of molecular electronics, where scientists aim for the smallest scale for electrical circuits, where the basic building blocks of modern electronics are based on molecules.

One example of this is molecular diodes (molecular devices capable of selecting the flow of charge current), which are of crucial importance as the basic building blocks of molecular circuitry - the future of powering our electronics.

The problem is that scientists have long seen molecular diodes behaving in either of the two Marcus regimes in ways they did not understand.

"We have seen similar molecules behaving in totally different ways, and very different molecules behaving very similarly without any apparent reason," del Barco said. "This is highly surprising at a time where our knowledge of molecular junctions has substantially advanced. With two electrodes and a molecule in between, the charge does not flow; it jumps. But there are times where it shows a barrier, and other times it doesn't, and this is what we've been working hard to figure out."

Working closely with his colleague in Singapore, the team experimented with electric fields and temperature to see how charge flows through different molecular diodes.

Finally, they found a molecule that allowed them to explore the two Marcus regimes, by changing its temperature dependence at will.

"This is a breakthrough. If we think about this complex molecule as two different units coupled together, when the charge jumps into one unit, it generates an electric field on the other, and vice versa," del Barco explained. "This internal electrical gating is proportional to the amount of charge in the molecule as a whole, which it increases with the voltage applied to the device, and makes the molecular diode to transit in between the two Marcus regimes. This is the first time we've seen such a transition in molecular electronics."

Aside from the important implications of this discovery in the field of chemistry, it turns out that this molecule represents the first molecular example of a double quantum dot, with exciting potential in physics. This puts molecular systems in emerging technologies such as quantum information and computation in view.

Quantum dots behave like atoms, but have more accessible energy levels to conduct electricity, making quantum dots an ideal way to power computers and other electronic devices.

Silicon is what powers our smartphones and computers today. In the future, molecular electronics may offer complementary functionalities beyond what is possible with Silicon. Silicon has limitations, and cannot go as small as molecular electronics can. Del Barco says in the future, molecular technology will be used in conjunction with silicon, to create novel electronics applications.

###

Del Barco and Nijuhuis' work, published in Nature Nanotechnology, will contribute to advancing the understanding of quantum technologies.

####

For more information, please click here

Contacts:
Allison Hurtado

407-823-0348

Copyright © University of Central Florida

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

The dispute about the origins of terahertz photoresponse in graphene results in a draw April 26th, 2018

Getting a better look at living cells April 25th, 2018

Graphene origami as a mechanically tunable plasmonic structure for infrared detection April 25th, 2018

Nuclear radiation detecting device could lead to new homeland security tool: New device can detect gamma rays and identify radioactive isotopes April 25th, 2018

Possible Futures

The dispute about the origins of terahertz photoresponse in graphene results in a draw April 26th, 2018

Getting a better look at living cells April 25th, 2018

Graphene origami as a mechanically tunable plasmonic structure for infrared detection April 25th, 2018

Nuclear radiation detecting device could lead to new homeland security tool: New device can detect gamma rays and identify radioactive isotopes April 25th, 2018

Chip Technology

Getting electrons to move in a semiconductor: Gallium oxide shows high electron mobility, making it promising for better and cheaper devices April 24th, 2018

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Salt boosts creation of 2-D materials: Rice University scientists show how salt lowers reaction temperatures to make novel materials April 18th, 2018

When superconductivity disappears in the core of a quantum tube: By replacing the electrons with ultra-cold atoms, a group of physicists has created a perfectly clean material, unveiling new states of matter at the quantum level April 16th, 2018

Quantum Computing

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Quantum shift shows itself in coupled light and matter: Rice University scientists corral, quantify subtle movement in condensed matter system April 16th, 2018

When superconductivity disappears in the core of a quantum tube: By replacing the electrons with ultra-cold atoms, a group of physicists has created a perfectly clean material, unveiling new states of matter at the quantum level April 16th, 2018

Quantum physicists achieve entanglement record: Largest entangled quantum register of individually controllable systems to date April 15th, 2018

Nanoelectronics

Getting electrons to move in a semiconductor: Gallium oxide shows high electron mobility, making it promising for better and cheaper devices April 24th, 2018

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Non-toxic filamentous virus helps quickly dissipate heat generated by electronic devices April 4th, 2018

Ancient paper art, kirigami, poised to improve smart clothing: New research shows how paper-cutting can make ultra strong, stretchable electronics April 3rd, 2018

Discoveries

The dispute about the origins of terahertz photoresponse in graphene results in a draw April 26th, 2018

Getting a better look at living cells April 25th, 2018

Graphene origami as a mechanically tunable plasmonic structure for infrared detection April 25th, 2018

Nuclear radiation detecting device could lead to new homeland security tool: New device can detect gamma rays and identify radioactive isotopes April 25th, 2018

Announcements

The dispute about the origins of terahertz photoresponse in graphene results in a draw April 26th, 2018

Getting a better look at living cells April 25th, 2018

Graphene origami as a mechanically tunable plasmonic structure for infrared detection April 25th, 2018

Nuclear radiation detecting device could lead to new homeland security tool: New device can detect gamma rays and identify radioactive isotopes April 25th, 2018

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

The dispute about the origins of terahertz photoresponse in graphene results in a draw April 26th, 2018

Getting a better look at living cells April 25th, 2018

Graphene origami as a mechanically tunable plasmonic structure for infrared detection April 25th, 2018

Nuclear radiation detecting device could lead to new homeland security tool: New device can detect gamma rays and identify radioactive isotopes April 25th, 2018

Research partnerships

Getting a better look at living cells April 25th, 2018

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Salt boosts creation of 2-D materials: Rice University scientists show how salt lowers reaction temperatures to make novel materials April 18th, 2018

Psst! A whispering gallery for light boosts solar cells April 14th, 2018

Quantum nanoscience

New qubit now works without breaks: A universal design for superconducting qubits has been created April 19th, 2018

Quantum shift shows itself in coupled light and matter: Rice University scientists corral, quantify subtle movement in condensed matter system April 16th, 2018

When superconductivity disappears in the core of a quantum tube: By replacing the electrons with ultra-cold atoms, a group of physicists has created a perfectly clean material, unveiling new states of matter at the quantum level April 16th, 2018

Phononic SEIRA -- enhancing light-molecule interactions via crystal lattice vibrations April 10th, 2018

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project