Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A step toward better electronics

20.02.2012
Researchers develop new way to oxidize promising graphene

Researchers at Northwestern University have developed a new method for chemically altering graphene, a development that could be a step toward the creation of faster, thinner, flexible electronics.

Highly desired for its many promising attributes, graphene is a one-atom thick, honeycomb-shaped lattice of carbon atoms with exceptional strength and conductivity. Among graphene's many possible applications is electronics: Many experts believe it could rival silicon, transforming integrated circuits and leading to ultra-fast computers, cellphones and related portable electronic devices.

But first, researchers must learn how to tune the electronic properties of graphene -- not an easy feat, given a major challenge intrinsic to the material. Unlike semiconductors such as silicon, pure graphene is a zero band-gap material, making it difficult to electrically "turn off" the flow of current through it. Therefore, pristine graphene is not appropriate for the digital circuitry that comprises the vast majority of integrated circuits.

To overcome this problem and make graphene more functional, researchers around the world are investigating methods for chemically altering the material. The most prevalent strategy is the "Hummers method," a process developed in the 1940s that oxidizes graphene, but that method relies upon harsh acids that irreversibly damage the fabric of the graphene lattice.

Researchers at Northwestern's McCormick School of Engineering and Applied Science have recently developed a new method to oxidize graphene without the collateral damage encountered in the Hummers method. Their oxidation process is also reversible, which enables further tunability over the resulting properties of their chemically modified graphene.

The paper, "Chemically Homogeneous and Thermally Reversible Oxidation of Epitaxial Graphene," will be published Feb. 19 in the journal Nature Chemistry.

"Performing chemical reactions on graphene is very difficult," said Mark C. Hersam, professor of materials science and engineering at the McCormick School. "Typically, researchers employ aggressive acidic conditions, such as those utilized in the Hummers method, that damage the lattice and result in a material that is difficult to control.

"In our method, however, the resulting graphene oxide is chemically homogeneous and reversible — leading to well-controlled properties that can likely be exploited in high-performance applications," said Hersam, who is also a professor of chemistry and of medicine.

To create the graphene oxide, researchers leaked oxygen gas (O2) into an ultra-high vacuum chamber. Inside, a hot tungsten filament was heated to 1500 degrees Celsius, causing the oxygen molecules to dissociate into atomic oxygen. The highly reactive oxygen atoms then uniformly inserted into the graphene lattice.

The resulting material possesses a high degree of chemical homogeneity. Spectroscopic measurements show that the electronic properties of the graphene vary as a function of oxygen coverage, suggesting that this approach can tune the properties of graphene-based devices. "It's unclear if this work will impact real-world applications overnight," Hersam said. "But it appears to be a step in the right direction."

Next, researchers will explore other means of chemically modifying graphene to develop a wider variety of materials, much like scientists did for plastics in the last century.

"Maybe oxygen isn't enough," Hersam said. "Through chemical modification, the scientific community has developed a wide range of polymers, from hard plastics to nylon. We hope to realize the same degree of tunability for graphene."

Megan Fellman | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Power and Electrical Engineering:

nachricht Linear potentiometer LRW2/3 - Maximum precision with many measuring points
17.05.2017 | WayCon Positionsmesstechnik GmbH

nachricht First flat lens for immersion microscope provides alternative to centuries-old technique
17.05.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Turmoil in sluggish electrons’ existence

23.05.2017 | Physics and Astronomy

“Pregnant” Housefly Males Demonstrate the Evolution of Sex Determination

23.05.2017 | Life Sciences

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>