Subscribe free to our newsletters via your
. 24/7 Space News .




ENERGY TECH
Visualizing interacting electrons in a molecule
by Staff Writers
Espoo, Finland (SPX) Jan 28, 2015


The image on left shows: Chemical structure of cobalt phthalocyanine (CoPC). The image on right shows: Experimental and theoretical wave functions of CoPC. Image courtesy Aalto University. For a larger version of this image please go here.

Understanding this kind of electronic effects in organic molecules is crucial for their use in optoelectronic applications, for example in organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs) and solar cells.

In their article published in Nature Physics, the research team demonstrates measurements on the organic molecule cobalt phthalocyanine (CoPC) that can be explained only by taking into consideration how electrons in the molecule interact with each other. CoPC is a commonly used molecule in organic optoelectronic devices. Electron-electron interactions alter its conductivity, which is directly related to device performance.

The Atomic Scale Physics group at Aalto University headed by Peter Liljeroth specializes on scanning tunneling microscopy (STM), which utilizes a tiny current between a sharp probe tip and a conducting sample to measure structural and electronic properties of the sample surface with atomic resolution. In this case, they used the STM to measure the current passing through a single molecule on a surface by injecting or removing electrons at different energies.

Within the molecule, electrons 'live' on so-called orbitals, which define their energy and the shape of their quantum mechanical wavefunction. These orbitals can be measured by recording the current through the molecule as a function of the applied voltage.

Fabian Schulz, a post-graduate researcher in Liljeroth's group, was surprised when the measurements on CoPC molecules did not fit the conventional interpretation of STM experiments on single molecules. "We saw several additional features in the recorded current where there should have been none according to the usual interpretation of these so-called tunneling spectra", Schulz explains.

The experiments were performed on cobalt phthalocyanine (CoPC) molecules deposited on a one-atom thick layer of hexagonal boron nitride on an iridium surface.

A colleague from Aalto University and leader of the Quantum Many-Body Physics group, Ari Harju, suggested that the key to understanding the experimental results might be a form of electron-electron interaction that usually is neglected in interpreting such experiments.

In collaboration with Ari P. Seitsonen from the University of Zurich, Ari Harju and his team calculated the electronic properties of the molecule, including quantum mechanical effects that went beyond prevailing methods.

This novel interpretation was confirmed when Liljeroth and his team were able to match the experimentally measured molecular orbitals with the predictions of the theory. "It was very exciting to see this kind of an interplay between theory and experiment", Liljeroth remarks.

Ari Harju concludes: "The proof that such theoretically predicted, exotic effects can be observed experimentally is an important step forward in understanding how current is transported across individual molecules and molecular assemblies."


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Aalto University
Powering The World in the 21st Century at Energy-Daily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








ENERGY TECH
Optic fiber for recording temps in extreme industrial environments
Madrid, Spain (SPX) Jan 23, 2015
The system they have developed is able to measure the temperature of mechanical or cutting processes in areas where conventional techniques do not have access. In these environments, thermographic infrared cameras cannot be used because there is not a clear line of vision to the tool's cutting point, nor can thermocouples or other sensors be applied because of the deterioration they will s ... read more


ENERGY TECH
Service Module of Chinese Probe Enters Lunar Orbit

Service module of China's lunar orbiter enters 127-minute orbit

Chinese spacecraft to return to moon's orbit

Russian Company Proposes to Build Lunar Base

ENERGY TECH
Helicopter Could be 'Scout' for Mars Rovers

Hilltop Panorama Marks Mars Rover's 11th Anniversary

Mysteries in Nili Fossae

NASA, Microsoft Collaboration Will Allow Scientists to 'Work on Mars'

ENERGY TECH
Sailing spacecraft LightSail to harness power of solar wind

Virgin Galactic Appoints Mark Stucky as Pilot

Singer Sarah Brightman in training for space tourist role

Stepping Stones to NASA's Human Missions Beyond

ENERGY TECH
More Astronauts for China

China launches the FY-2 08 meteorological satellite successfully

China's Long March puts satellite in orbit on 200th launch

Countdown to China's new space programs begins

ENERGY TECH
NASA's CATS Installed on ISS by Robotic Handoff

Roscosmos, NASA Still Planning on Sending Men Into Space

Russian Cargo Spacecraft to Supply ISS With Black Caviar

Astronauts' year-long mission will test limits

ENERGY TECH
Soyuz Installed at Baikonur, Expected to Launch Wednesday

Elon Musk says SpaceX using electric rockets is 'impossible' after 'Simpsons' episode

SES Entrusts Arianespace With SES-12

Google aboard as Musk's SpaceX gets $1 bn in funding

ENERGY TECH
Ancient star system has Earth-sized planets forming near start of universe

Gigantic ring system around J1407b much larger, heavier than Saturn's

New research re-creates planet formation in the lab

Planets outside our solar system more hospitable to life than thought

ENERGY TECH
Is glass a true solid?

Scientists 'bend' elastic waves with new metamaterials

Scientists 'bend' acoustic and elastic waves with new metamaterials

Planetary Society announces test flight for LightSail




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.