Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Rice technique points toward 2-D devices: Researchers create fine patterns that combine single-atom-thick graphene, boron nitride

An atom-thick Rice Owl (scale bar equals 100 micrometers) was created to show the ability to make fine patterns in hybrid graphene/hexagonal boron nitride (hBN). In this image, the owl is hBN and the lighter material around it is graphene. The ability to pattern a conductor (graphene) and insulator (hBN) into a single layer may advance the ability to shrink electronic devices. (Credit: Zheng Liu/Rice University)
An atom-thick Rice Owl (scale bar equals 100 micrometers) was created to show the ability to make fine patterns in hybrid graphene/hexagonal boron nitride (hBN). In this image, the owl is hBN and the lighter material around it is graphene. The ability to pattern a conductor (graphene) and insulator (hBN) into a single layer may advance the ability to shrink electronic devices.

(Credit: Zheng Liu/Rice University)

Abstract:
Rice University scientists have taken an important step toward the creation of two-dimensional electronics with a process to make patterns in atom-thick layers that combine a conductor and an insulator.

Rice technique points toward 2-D devices: Researchers create fine patterns that combine single-atom-thick graphene, boron nitride

Houston, TX | Posted on January 27th, 2013

The materials at play - graphene and hexagonal boron nitride - have been merged into sheets and built into a variety of patterns at nanoscale dimensions.

Rice introduced a technique to stitch the identically structured materials together nearly three years ago. Since then, the idea has received a lot of attention from researchers interested in the prospect of building 2-D, atomic-layer circuits, said Rice materials scientist Pulickel Ajayan. He is one of the authors of the new work that appears this week in Nature Nanotechnology. In particular, Ajayan noted that Cornell University scientists reported an advance late last year on the art of making atomic-layer heterostructures through sequential growth schemes.

This week's contribution by Rice offers manufacturers the possibility of shrinking electronic devices into even smaller packages. While Rice's technical capabilities limited features to a resolution of about 100 nanometers, the only real limits are those defined by modern lithographic techniques, according to the researchers. (A nanometer is one-billionth of a meter.)

"It should be possible to make fully functional devices with circuits 30, even 20 nanometers wide, all in two dimensions," said Rice researcher Jun Lou, a co-author of the new paper. That would make circuits on about the same scale as in current semiconductor fabrication, he said.

Graphene has been touted as a wonder material since its discovery in the last decade. Even at one atom thick, the hexagonal array of carbon atoms has proven its potential as a fascinating electronic material. But to build a working device, conductors alone will not do. Graphene-based electronics require similar, compatible 2-D materials for other components, and researchers have found hexagonal boron nitride (h-BN) works nicely as an insulator.

H-BN looks like graphene, with the same chicken-wire atomic array. The earlier work at Rice showed that merging graphene and h-BN via chemical vapor deposition (CVD) created sheets with pools of the two that afforded some control of the material's electronic properties. Ajayan said at the time that the creation offered "a great playground for materials scientists."

He has since concluded that the area of two-dimensional materials beyond graphene "has grown significantly and will play out as one of the key exciting materials in the near future."

His prediction bears fruit in the new work, in which finely detailed patterns of graphene are laced into gaps created in sheets of h-BN. Combs, bars, concentric rings and even microscopic Rice Owls were laid down through a lithographic process. The interface between elements, seen clearly in scanning transmission electron microscope images taken at Oak Ridge National Laboratories, shows a razor-sharp transition from graphene to h-BN along a subnanometer line.

"This is not a simple quilt," Lou said. "It's very precisely engineered. We can control the domain sizes and the domain shapes, both of which are necessary to make electronic devices."

The new technique also began with CVD. Lead author Zheng Liu, a Rice research scientist, and his colleagues first laid down a sheet of h-BN. Laser-cut photoresistant masks were placed over the h-BN, and exposed material was etched away with argon gas. (A focused ion beam system was later used to create even finer patterns, down to 100-nanometer resolution, without masks.) After the masks were washed away, graphene was grown via CVD in the open spaces, where it bonded edge-to-edge with the h-BN. The hybrid layer could then be picked up and placed on any substrate.

While there's much work ahead to characterize the atomic bonds where graphene and h-BN domains meet and to analyze potential defects along the boundaries, Liu's electrical measurements proved the components' qualities remain intact.

"One important thing Zheng showed is that even by doing all kinds of growth, then etching, then regrowth, the intrinsic properties of these two materials are not affected," Lou said. "Insulators stay insulators; they're not doped by the carbon. And the graphene still looks very good. That's important, because we want to be sure what we're growing is exactly what we want."

Liu said the next step is to place a third element, a semiconductor, into the 2-D fabric. "We're trying very hard to integrate this into the platform," he said. "If we can do that, we can build truly integrated in-plane devices." That would give new options to manufacturers toying with the idea of flexible electronics, he said.

"The contribution of this paper is to demonstrate the general process," Lou added. "It's robust, it's repeatable and it creates materials with very nice properties and with dimensions that are at the limit of what is possible."

Co-authors of the paper are graduate students Lulu Ma, Gang Shi, Yongji Gong, Ken Hackenberg, Sidong Lei and Jiangnan Zhang; Aydin Babakhani, an assistant professor of electrical and computer engineering; and Robert Vajtai, a faculty fellow in mechanical engineering and materials science, all at Rice; Wu Zhou, a research associate at Vanderbilt University and Wigner Fellow at Oak Ridge National Laboratory; Xuebei Yang, a former research assistant at Rice, now at Agilent Technologies; Jingjiang Yu, a scientist at Agilent Technologies; and Juan-Carlos Idrobo, a research professor of physics at Vanderbilt and a guest scientist at Oak Ridge. Lou is an associate professor of mechanical engineering and materials science. Ajayan is the Benjamin M. and Mary Greenwood Anderson Professor in Mechanical Engineering and Materials Science and of chemistry at Rice.

The work was supported by U.S. Army Research Office and U.S. Office of Naval Research Multidisciplinary University Research Initiative grants; the Nanoelectronics Research Corp; a U.S.-Japan Cooperative Research and Education in Terahertz grant; the Welch Foundation; the National Science Foundation; and Oak Ridge National Laboratory's Shared Research Equipment User Program, sponsored by the Office of Basic Energy Sciences, U.S. Department of Energy.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,708 undergraduates and 2,374 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to tinyurl.com/AboutRice.

Follow Rice News and Media Relations via Twitter @RiceUNews

For more information, please click here

Contacts:
David Ruth

713-348-6327

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Lou Group:

Ajayan Group:

Graphene and boron nitride lateral heterostructures for atomically thin circuitry:

Related News Press

News and information

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

National Space Society Congratulates SpaceX on the Falcon 9's Return to Flight January 19th, 2017

Eric Berger Wins the National Space Society's 2017 Space Pioneer Award for Mass Media January 19th, 2017

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 7, 2017 January 19th, 2017

Laboratories

Nanoscale view of energy storage January 16th, 2017

Chemistry on the edge: Experiments at Berkeley Lab confirm that structural defects at the periphery are key in catalyst function January 13th, 2017

Recreating conditions inside stars with compact lasers: Scientists offer a new path to creating the extreme conditions found in stars, using ultra-short laser pulses irradiating nanowires January 12th, 2017

NIST physicists 'squeeze' light to cool microscopic drum below quantum limit January 12th, 2017

Nanoscale 'conversations' create complex, multi-layered structures: New technique leverages controlled interactions across surfaces to create self-assembled materials with unprecedented complexity December 22nd, 2016

Graphene/ Graphite

Researchers design one of the strongest, lightest materials known: Porous, 3-D forms of graphene developed at MIT can be 10 times as strong as steel but much lighter January 7th, 2017

Nano-chimneys can cool circuits: Rice University scientists calculate tweaks to graphene would form phonon-friendly cones January 4th, 2017

First use of graphene to detect cancer cells: System able to detect activity level of single interfaced cell December 20th, 2016

Govt.-Legislation/Regulation/Funding/Policy

'5-D protein fingerprinting' could give insights into Alzheimer's, Parkinson's January 19th, 2017

Strength of hair inspires new materials for body armor January 18th, 2017

Self-assembling particles brighten future of LED lighting January 18th, 2017

Nanoscale view of energy storage January 16th, 2017

Chip Technology

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 7, 2017 January 19th, 2017

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Seeing the quantum future... literally: What if big data could help you see the future and prevent your mobile phone from breaking before it happened? January 16th, 2017

NUS researchers achieve major breakthrough in flexible electronics: New classes of printable electrically conducting polymer materials make better electrodes for plastic electronics and advanced semiconductor devices January 14th, 2017

Discoveries

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

'5-D protein fingerprinting' could give insights into Alzheimer's, Parkinson's January 19th, 2017

Strength of hair inspires new materials for body armor January 18th, 2017

Self-assembling particles brighten future of LED lighting January 18th, 2017

Announcements

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

National Space Society Congratulates SpaceX on the Falcon 9's Return to Flight January 19th, 2017

Eric Berger Wins the National Space Society's 2017 Space Pioneer Award for Mass Media January 19th, 2017

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 7, 2017 January 19th, 2017

Military

'5-D protein fingerprinting' could give insights into Alzheimer's, Parkinson's January 19th, 2017

Strength of hair inspires new materials for body armor January 18th, 2017

Self-assembling particles brighten future of LED lighting January 18th, 2017

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Research partnerships

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

Chemistry on the edge: Experiments at Berkeley Lab confirm that structural defects at the periphery are key in catalyst function January 13th, 2017

Recreating conditions inside stars with compact lasers: Scientists offer a new path to creating the extreme conditions found in stars, using ultra-short laser pulses irradiating nanowires January 12th, 2017

Zeroing in on the true nature of fluids within nanocapillaries: While exploring the behavior of fluids at the nanoscale, a group of researchers at the French National Center for Scientific Research discovered a peculiar state of fluid mixtures contained in microscopic channels January 11th, 2017

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project