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 Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>