Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How to create nanowires only 3 atoms wide with an electron beam

28.04.2014

Junhao Lin, a Vanderbilt University Ph.D. student and visiting scientist at Oak Ridge National Laboratory (ORNL), has found a way to use a finely focused beam of electrons to create some of the smallest wires ever made. The flexible metallic wires are only three atoms wide: One thousandth the width of the microscopic wires used to connect the transistors in today's integrated circuits.

Lin's achievement is described in an article published online on April 28 by the journal Nature Nanotechnology. According to his advisor Sokrates Pantelides, University Distinguished Professor of Physics and Engineering at Vanderbilt University, and his collaborators at ORNL, the technique represents an exciting new way to manipulate matter at the nanoscale and should give a boost to efforts to create electronic circuits out of atomic monolayers, the thinnest possible form factor for solid objects.


This is a molecular model showing the structure of the nanowires created out of a monolayer of transition-metal dichalcogenides (TMDCs).

Credit: Junhao Lin, Vanderbilt University

"Junhao took this project and really ran with it," said Pantelides.

Lin made the tiny wires from a special family of semiconducting materials that naturally form monolayers. These materials, called transition-metal dichalcogenides (TMDCs), are made by combining the metals molybdenum or tungsten with either sulfur or selenium. The best-known member of the family is molybdenum disulfide, a common mineral that is used as a solid lubricant.

Atomic monolayers are the object of considerable scientific interest these days because they tend to have a number of remarkable qualities, such as exceptional strength and flexibility, transparency and high electron mobility. This interest was sparked in 2004 by the discovery of an easy way to create graphene, an atomic-scale honeycomb lattice of carbon atoms that has exhibited a number of record-breaking properties, including strength, electricity and heat conduction.

Despite graphene's superlative properties, experts have had trouble converting them into useful devices, a process materials scientists call functionalization. So researchers have turned to other monolayer materials like the TMDCs.

Other research groups have already created functioning transistors and flash memory gates out of TMDC materials. So the discovery of how to make wires provides the means for interconnecting these basic elements. Next to the transistors, wiring is one of the most important parts of an integrated circuit. Although today's integrated circuits (chips) are the size of a thumbnail, they contain more than 20 miles of copper wiring.

"This will likely stimulate a huge research interest in monolayer circuit design," Lin said. "Because this technique uses electron irradiation, it can in principle be applicable to any kind of electron-based instrument, such as electron-beam lithography."

One of the intriguing properties of monolayer circuitry is its toughness and flexibility. It is too early to predict what kinds of applications it will produce, but "If you let your imagination go, you can envision tablets and television displays that are as thin as a sheet of paper that you can roll up and stuff in your pocket or purse," Pantelides commented.

In addition, Lin envisions that the new technique could make it possible to create three-dimensional circuits by stacking monolayers "like Lego blocks" and using electron beams to fabricate the wires that connect the stacked layers.

The nanowire fabrication was carried out at ORNL in the microscopy group that was headed until recently by Stephen J. Pennycook, as part of an ongoing Vanderbilt-ORNL collaboration that combines microscopy and theory to study complex materials systems. Junhao is a graduate student who pursues both theory and electron microscopy in his doctoral research. His primary microscopy mentor has been ORNL Wigner Fellow Wu Zhou.

"Junhao used a scanning transmission electron microscope (STEM) that is capable of focusing a beam of electrons down to a width of half an angstrom (about half the size of an atom) and aims this beam with exquisite precision," Zhou said.

The collaboration included a group headed by Kazu Suenaga at the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan, where the electrical measurements that confirmed the theoretical predictions were made by post-doctoral associate Ovidiu Cretu. Other collaborators at ORNL, the University of Tennessee in Knoxville, Vanderbilt University, and Fisk University contributed to the project.

Primary funding for the research was provided by the Department of Energy's Office of Science grant DE-FG02-09ER46554 and by the ORNL Wigner Fellowship. The work was carried at the ORNL Center for Nanophase Materials Science user facility. Computations were done at the National Energy Research Scientific Computer Center.

David Salisbury | Vanderbilt University

Further reports about: Engineering ORNL Vanderbilt materials measurements molybdenum monolayer nanowires properties transistors

More articles from Physics and Astronomy:

nachricht Hubble survey unlocks clues to star birth in neighboring galaxy
04.09.2015 | NASA/Goddard Space Flight Center

nachricht Tiny Drops of Early Universe 'Perfect' Fluid
02.09.2015 | Brookhaven National Laboratory

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Hubble survey unlocks clues to star birth in neighboring galaxy

In a survey of NASA's Hubble Space Telescope images of 2,753 young, blue star clusters in the neighboring Andromeda galaxy (M31), astronomers have found that M31 and our own galaxy have a similar percentage of newborn stars based on mass.

By nailing down what percentage of stars have a particular mass within a cluster, or the Initial Mass Function (IMF), scientists can better interpret the light...

Im Focus: Fraunhofer ISE Develops Highly Compact Inverter for Uninterruptible Power Supplies

Silicon Carbide Components Enable Efficiency of 98.7 percent

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have developed a highly compact and efficient inverter for use in uninterruptible power...

Im Focus: How wind sculpted Earth's largest dust deposit

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed.

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from...

Im Focus: An engineered surface unsticks sticky water droplets

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.

Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient...

Im Focus: Increasingly severe disturbances weaken world's temperate forests

Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.

"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Together - Work - Experience

03.09.2015 | Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

 
Latest News

Ion implanted, co-annealed, screen-printed 21% efficient n-PERT solar cells with a bifaciality >97%

04.09.2015 | Power and Electrical Engineering

Casting of SiSiC: new perspectives for chemical and plant engineering

04.09.2015 | Machine Engineering

Extremely thin ceramic components made possible by extrusion

04.09.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>