Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemists measure copper levels in zinc oxide nanowires

21.02.2008
Chemists at the National Institute of Standards and Technology (NIST) have been the first to measure significant amounts of copper incorporated into zinc oxide (ZnO) nanowires during fabrication. The issue is important because copper plays a significant—but not well-understood—role in important optical and electrical properties of the nanowires. Previous experiments found only trace amounts of copper.

Although zinc oxide is best known as a strong sunblock, cold remedy, itch reliever and paint pigment, nanotech engineers like it for its photoluminescence (the ability to emit light after absorbing electromagnetic radiation), field emission (the basis for advanced, high-definition flat-panel displays) and piezoelectric properties (stressing or changing shape when electricity is applied and producing electricity when stressed). ZnO nanomaterials may one day be used to improve solar cells, lasers, sensors, ultraviolet light sources, field emission sources and piezoelectric devices.

Copper enters the ZnO nanowires during fabrication. The nanowires—about 50 to 150 nanometers wide and up to 40 micrometers long—are grown on a copper substrate using a chemical vapor deposition process. The copper substrate forms droplets that absorb the zinc and oxygen vapors and deposits the ZnO on the substrate. As the nanowire grows, the zinc pushes the droplets up from the surface, but some copper remains inside the nanowire’s crystal lattice.

In a new paper,* NIST chemists report using a variety of measurement techniques to learn that the ZnO wires contain a surprising amount of copper—between 5 and 15 percent. High-resolution imaging studies of ZnO nanowires reveal that the copper manages to fit into zinc oxide’s regular crystalline structure without disrupting it. “It is in there somewhere,” explains chemist Susie Eustis. Because the copper can be easily detected when you know what to look for, she says, researchers plan to use it to better understand the crystal structure of ZnO nanowires with an eye toward manipulating the nanowires to improve performance. “The copper acts like a smart tag that you put on an animal in the wild to trace where it travels,” says Eustis.

... more about:
»Oxide »ZnO »copper »nanowire »zinc

The role copper plays in ZnO nanowires is ambiguous. Published studies differ on whether the copper increases or decreases the nanowires’ photoluminescence. Eustis and colleagues found that the copper in the nanowire increases the output of visible light but at the expense of ultraviolet emission.

In addition to determining the role copper plays in ZnO nanowires, the researchers plan to learn how to grow uniform nanowires that may one day be used in commercial products. This research is part of ongoing studies to find the best methods to determine the concentration and distribution of atoms inside nanostructures.

Evelyn Brown | EurekAlert!
Further information:
http://www.nist.gov

Further reports about: Oxide ZnO copper nanowire zinc

More articles from Life Sciences:

nachricht Fish recognize their prey by electric colors
13.11.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht The dawn of a new era for genebanks - molecular characterisation of an entire genebank collection
13.11.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Chip with Blood Vessels

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...

Im Focus: A Leap Into Quantum Technology

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...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

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...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

The dawn of a new era for genebanks - molecular characterisation of an entire genebank collection

13.11.2018 | Life Sciences

Fish recognize their prey by electric colors

13.11.2018 | Life Sciences

Ultrasound Connects

13.11.2018 | Awards Funding

VideoLinks
Science & Research
Overview of more VideoLinks >>>