Featured Research

from universities, journals, and other organizations

Controlling The Electronic Surface Properties Of A Material

Date:
July 20, 2009
Source:
Paul Scherrer Institut (PSI)
Summary:
Researchers in Switzerland have for the first time created thin films with controllable electronic properties. This discovery could have a large impact on future applications in sensors and computing.

A two-dimensional “electronic metamaterial” is generated by supramolecular selfassembly on a metal surface. The periodic influence of the porous molecular network on the otherwise free-electron-like surface state results in the formation of an electronic band.
Credit: Image courtesy of Paul Scherrer Institut (PSI)

It's commonly accepted that electrical resistance of a given material cannot be adjusted as is the case with, for example, density and color. However, Dr Meike Stöhr and her collaborators have now succeeded in developing a new method to selectively tune surface properties such as resistance.

The interdisciplinary team of physicists and chemists have developed a substance which, after heating on a copper surface, exhibits a two dimensional network with nanometer sized pores. The interaction of this network with the existing electron gas on the metal surface leads to the following effect: the electrons underneath the network are pushed into the pores to form small bunches of electrons called quantum dots.

Great potential for materials research

By varying parameters such as the height and diameter of the pores the possibility arises to selectively tune the properties of the material. Further possibilities arise from the ability to fill the pores with different molecules. This allows direct access to the properties of the material which are dependent on the electronic structure, such as conductivity, reflectivity and surface catalysis properties. This will lead to the emergence of new materials with adjustable electronic properties.

The underlying physical mechanisms can best be understood by a comparison of the electron-gas with waves in water. Waves on a water surface are reflected by any obstacle they meet. If the obstacle on the surface in question resembles a honeycomb structure, standing waves are set up in each cell of the honeycomb. This then leads to a wave pattern representative of the honeycomb structure of the same size and shape. “Applying this analogy to the electron gas, we see that the interaction of the network structure with the electron gas on the metal surface confines the electrons giving rise to a characteristic electron wave structure of the new material.” says Stöhr.

These pore networks are good candidates for new meta-materials. These are man-made materials which, due to their period architecture, have specific optical and electronic properties not found in nature. These properties can be tuned by changing the properties of their component materials. In the case of pore networks, it is the electronic surface properties which can be tuned by careful selection of the nano-pores.

The University of Basel and the Paul Scherrer Institute are long-term partners of the Swiss Nanoscience Institute (SNI), which is also financed by the Canton of Aargau. The SNI also includes both the Nationaler Forschungsschwerpunkt Nanowissenschaften which was founded in 2001, and the Argovia-Netzwerk, founded in 2006 and also financed by the Canton of Aargau. A key partner in this project was the Swiss Light Source of the Paul Scherrer institute.


Story Source:

The above story is based on materials provided by Paul Scherrer Institut (PSI). Note: Materials may be edited for content and length.


Journal Reference:

  1. Jorge Lobo-Checa, Manfred Matena, Kathrin Müller, Jan Hugo Dil, Fabian Meier, Lutz H. Gade, Thomas A. Jung, Meike Stöhr. Band Formation from Coupled Quantum Dots Formed by a Nanoporous Network on a Copper Surface. Science, 2009; 325 (5938): 300 DOI: 10.1126/science.1175141

Cite This Page:

Paul Scherrer Institut (PSI). "Controlling The Electronic Surface Properties Of A Material." ScienceDaily. ScienceDaily, 20 July 2009. <www.sciencedaily.com/releases/2009/07/090716164447.htm>.
Paul Scherrer Institut (PSI). (2009, July 20). Controlling The Electronic Surface Properties Of A Material. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2009/07/090716164447.htm
Paul Scherrer Institut (PSI). "Controlling The Electronic Surface Properties Of A Material." ScienceDaily. www.sciencedaily.com/releases/2009/07/090716164447.htm (accessed July 30, 2014).

Share This




More Matter & Energy News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) — British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
China's Drone King Says the Revolution Depends on Regulators

China's Drone King Says the Revolution Depends on Regulators

Reuters - Business Video Online (July 30, 2014) — Comparing his current crop of drones to early personal computers, DJI founder Frank Wang says the industry is poised for a growth surge - assuming regulators in more markets clear it for takeoff. Jon Gordon reports. Video provided by Reuters
Powered by NewsLook.com
Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) — A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Stranded Whale Watching Boat Returns to Boston

Stranded Whale Watching Boat Returns to Boston

Reuters - US Online Video (July 29, 2014) — Passengers stuck overnight on a whale watching boat return safely to Boston. Linda So reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins