Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Researchers Stitch Defects into the World’s Thinnest Semiconductor

A false-color electron microscopy image showing the star-shaped crystals in monolayers of two-dimensional semiconducting molybdenum disulfide. The red, yellow, and blue colors represent two dominant crystal orientations that are stitched together by a line of atomic defects. Image courtesy of Pinshane Y. Huang and David A. Muller
A false-color electron microscopy image showing the star-shaped crystals in monolayers of two-dimensional semiconducting molybdenum disulfide. The red, yellow, and blue colors represent two dominant crystal orientations that are stitched together by a line of atomic defects.

Image courtesy of Pinshane Y. Huang and David A. Muller

Abstract:
In pioneering new research at Columbia University, scientists have grown high-quality crystals of molybdenum disulfide (MoS2), the world's thinnest semiconductor, and studied how these crystals stitch together at the atomic scale to form continuous sheets. Through beautiful images of strikingly symmetric stars and triangles hundreds of microns across, they have uncovered key insights into the optical and electronic properties of this new material, which can be either conducting or insulating to form the basic "on-off switch" for all digital electronics. The study is published in the May 5, 2013, issue of Nature Materials.

Researchers Stitch Defects into the World’s Thinnest Semiconductor

New York, NY | Posted on May 22nd, 2013

"Our research is the first to systematically examine what kinds of defects result from these large growths, and to investigate how those defects change its properties," says James Hone, professor of mechanical engineering at Columbia Engineering, who led the study. "Our results will help develop ways to use this new material in atomically thin electronics that will become integral components of a whole new generation of revolutionary products such as flexible solar cells that conform to the body of a car."

This multidisciplinary collaboration by the Energy Frontier Research Center at Columbia University with Cornell University's Kavli Institute for Nanoscale Science focused on molybdenum disulfide because of its potential to create anything from highly efficient, flexible solar cells to conformable touch displays. Earlier work from Columbia demonstrated that monolayer MoS2 has an electronic structure distinct from the bulk form, and the researchers are excited about exploring other atomically thin metal dichalcogenides, which should have equally interesting properties. MoS2 is in a class of materials called transition metal dichalcogenides, which can be metals, semiconductors, dielectrics, and even superconductors.

"This material is the newest in a growing family of two-dimensional crystals," says Arend van der Zande, a research fellow at the Columbia Energy Frontier Research Center and one of the paper's three lead authors. "Graphene, a single sheet of carbon atoms, is the thinnest electrical conductor we know. With the addition of the monolayer molybdenum disulfide and other metal dichalcogenides, we have all the building blocks for modern electronics that must be created in atomically thin form. For example, we can now imagine sandwiching two different monolayer transition metal dichalcogenides between layers of graphene to make solar cells that are only eight atoms thick—20 thousand times smaller than a human hair!"

Until last year, the majority of experiments studying MoS2 were done by a process called mechanical exfoliation, which only produces samples just a few micrometers in size. "While these tiny specimens are fine for scientific studies," notes Daniel Chenet, a PhD in Hone's lab and another lead author, "they are much too small for use in any technological application. Figuring out how to grow these materials on a large scale is critical."

To study the material, the researchers refined an existing technique to grow large, symmetric crystals up to 100 microns across, but only three atoms thick. "If we could expand one of these crystals to the thickness of a sheet of plastic wrap, it would be large enough to cover a football field—and it would not have any misaligned atoms," says Pinshane Huang, a PhD student in the David Muller lab at Cornell and the paper's third lead author.

For use in many applications, these crystals need to be joined together into continuous sheets like patches on a quilt. The connections between the crystals, called grain boundaries, can be as important as the crystals themselves in determining the material's performance on a large scale. "The grain boundaries become important in any technology," says Hone. "Say, for example, we want to make a solar cell. Now we need to have meters of this material, not micrometers, and that means that there will be thousands of grain boundaries. We need to understand what they do so we can control them."

The team used atomic-resolution electron microscopy to examine the grain boundaries of this material, and saw lines of misaligned atoms. Once they knew where to find the grain boundaries, and what they looked like, the team could study the effect of a single grain boundary on the properties of the MoS2. To do this, they built tiny transistors, the most basic component in all of electronics, out of the crystals and saw that the single, defective line of atoms at the grain boundaries could drastically change the key electronic and optical properties of the MoS2.

"We've made a lot of progress in controlling the growth of this new ‘wonder' nanomaterial and are now developing techniques to integrate it into many new technologies," Hone adds. "We're only just beginning to scratch the surface of what we can make with these materials and what their properties are. For instance, we can easily remove this material from the growth substrate and transfer it on to any arbitrary surface, which enables us to integrate it into large-scale, flexible electronics and solar cells."

The crystal synthesis, optical measurements, electronic measurements, and theory were all performed by research groups at Columbia Engineering. The growth and electrical measurements were made by the Hone lab in mechanical engineering; the optical measurements were carried out in the Tony Heinz lab in physics. The structural modeling and electronic structure calculations were performed by the David Reichman lab in chemistry. The electron microscopy was performed by atomic imaging experts in the David Muller lab at Cornell University's School of Applied and Engineering Physics, and the Kavli Institute at Cornell for Nanoscale Science.

The study was sponsored by the Columbia Energy Frontier Research Center, with additional support provided by the National Science Foundation through the Cornell Center for Materials Research.

####

For more information, please click here

Contacts:
Holly Evarts
Director
Strategic Communications and Media Relations
347-453-7408 (c)
212-854-3206 (o)

Copyright © Columbia Engineering

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 News Press

News and information

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

Conductive Inks: booming to $2.8 billion by 2024 April 17th, 2014

Harris & Harris Group Continues Its Blog Series to Highlight Most Impactful Portfolio Companies With Champions Oncology, Inc. April 17th, 2014

Flexible Electronics

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Printed Electronics Europe - Plastic Logic shows a flexible OLED display for wearable devices April 11th, 2014

IDTechEx Printed Electronics Europe 2014 Award Winners April 1st, 2014

Chip Technology

'Exotic' material is like a switch when super thin April 18th, 2014

Scientists open door to better solar cells, superconductors and hard-drives: Research enhances understanding of materials interfaces April 14th, 2014

Obducat has launched a new generation of SINDRE® Nano Imprint production system April 11th, 2014

Scientists in Singapore develop novel ultra-fast electrical circuits using light-generated tunneling currents April 10th, 2014

Discoveries

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Thinnest feasible membrane produced April 17th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

Announcements

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

Thinnest feasible membrane produced April 17th, 2014

Tools

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Aerotech X-Y ball-screw stage for economical high performance Planar positioning April 16th, 2014

Energy

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Engineers develop new materials for hydrogen storage April 15th, 2014

A molecular approach to solar power: Switchable material could harness the power of the sun — even when it’s not shining April 15th, 2014

Automotive/Transportation

Relieving electric vehicle range anxiety with improved batteries: Lithium-sulfur batteries last longer with nanomaterial-packed cathode April 16th, 2014

Tiny particles could help verify goods: Chemical engineers hope smartphone-readable microparticles could crack down on counterfeiting April 15th, 2014

Nanotech Business Review 2013-2014 April 9th, 2014

Heat-conducting polymer cools hot electronic devices at 200 degrees C March 31st, 2014

Research partnerships

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Scalable CVD process for making 2-D molybdenum diselenide: Rice, NTU scientists unveil CVD production for coveted 2-D semiconductor April 8th, 2014

Carbon nanotubes grow in combustion flames April 1st, 2014

Solar/Photovoltaic

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

A molecular approach to solar power: Switchable material could harness the power of the sun — even when it’s not shining April 15th, 2014

Shiny quantum dots brighten future of solar cells: Photovoltaic solar-panel windows could be next for your house April 14th, 2014

Scientists open door to better solar cells, superconductors and hard-drives: Research enhances understanding of materials interfaces April 14th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE