Navigation Links
A step toward better electronics
Date:2/20/2012

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."


'/>"/>
Contact: Megan Fellman
fellman@northwestern.edu
847-491-3115
Northwestern University
Source:Eurekalert

Related biology technology :

1. First Product Candidate Moving Toward Commercialization as Result of Novus International and Verenium Collaboration
2. Terminator-style info-vision takes step towards reality
3. A step towards new vaccines for most important chicken parasite
4. Mendel Trait Technology Advances Towards Commercial Launch
5. Citizens Bank Provides $70 Million in Financing Toward $100 Million Expansion of The Wistar Institute
6. Innovation is step toward digital graphene transistors
7. Kibow Biotech, Inc. Secures $2.4 Million Towards Its Human Clinical Trials by Continued Veterinary Licensing Agreement
8. Scientists take a step towards developing better vaccines for bluetongue
9. Arteriocyte Receives $1 Million Award From Ohio Third Frontier Program to Advance Its NANEX™ Technology Toward Clinical Use
10. U.Va.s Pfister accomplishes breakthrough toward quantum computing
11. CPTA Takes a Step Toward Improving Patient Access to Physical Therapy Services
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/20/2017)... ... February 20, 2017 , ... Global relationship marketing company ... for full, active membership in the Canadian Direct Sellers Association (DSA) effective immediately. ... Officer Jeff Olson in 2011. Today Nerium International, with its cutting ...
(Date:2/20/2017)... 2017 This report analyzes the worldwide markets for ... Xylanase, Amylase, Cellulase, and Others. The report provides separate comprehensive ... Japan , Europe , ... and Rest of World. Read the full ... are provided for the period 2015 through 2022. Also, a ...
(Date:2/20/2017)... (PRWEB) , ... February 20, ... ... leading US Joint Commission Accredited venture-backed teleradiology and telemedicine company announces at ... Healthineers. USARAD services are planned to be offered via a global cloud-based ...
(Date:2/20/2017)... , Feb. 20, 2017  Former NFL players who ... motor functions later in life, according to a preliminary study ... of Neurology,s 69th Annual Meeting in Boston ... functions are complex movements where the muscles and nerves work ... ...
Breaking Biology Technology:
(Date:2/8/2017)... 7, 2017  Aware, Inc. (NASDAQ: AWRE ), ... financial results for its quarter and year ended December 31, ... 2016 was $3.9 million compared to $6.9 million in the ... of 2016 was $0.6 million compared to $2.6 million in ... quarter of 2016 was $0.5 million, or $0.02 per diluted ...
(Date:2/7/2017)... Zimmer Biomet Holdings, Inc. (NYSE and SIX: ... at the LEERINK Partners 6th Annual Global Healthcare Conference ... February 15, 2017 at 10 a.m. Eastern Time. ... be accessed at http://wsw.com/webcast/leerink28/zbh .  The webcast will ... Biomet,s Investor Relations website at http://investor.zimmerbiomet.com . ...
(Date:2/2/2017)... 2, 2017   TapImmune, Inc. (NASDAQ: ... specializing in the development of innovative peptide and ... cancer and metastatic disease, announced today it has ... of a second clinical lot of TPIV 200, ... alpha. The manufactured vaccine product will be used ...
Breaking Biology News(10 mins):