Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Making New Materials an Atomic Layer at a Time

18.04.2014

Researchers at Penn State’s Center for 2-Dimensional and Layered Materials and the University of Texas at Dallas have shown the ability to grow high quality, single-layer materials one on top of the other using chemical vapor deposition.

 This highly scalable technique, often used in the semiconductor industry, can produce new materials with unique properties that could be applied to solar cells, ultracapacitors for energy storage, or advanced transistors for energy efficient electronics, among many other applications.


Yu-Chuan Lin, Penn State

A photosensor fabricated on the MoS2/graphene heterostructure

“People have been trying to stack these layered materials using the scotch tape method (an exfoliation method developed by Nobel laureates Novoselov and Geim to produce graphene), but that leaves residue on the layers and is not scalable,” explains Joshua Robinson of Penn State, corresponding author on a recent article published online in ACS Nano. Other groups have utilized the chemical vapor deposition method to grow layered materials on a copper substrate, but this method requires some sophisticated techniques to transfer the layered material to a more functional substrate without causing tears or contamination.

Robinson and his colleagues employed a more direct method, using chemical vapor deposition to grow a layer of quasi-free-standing epitaxial graphene (QFEG) on a silicon carbide substrate, followed by a layer of molybdenum disulfide (MoS2), a metal dichalcogenide compound widely used as a lubricant. In order to test the quality of the MoS2 on graphene, the researchers used the material to build a photodetector device to measure the layered material’s efficiency at converting photons to electrons. They found that the response of the MoS2/QFEG material was 100 times higher than MoS2 alone.

... more about:
»ACS »Atomic »Layer »MoS2 »Nano »carbide »graphene »materials »photodetector

For devices, the QFEG method, which introduces a layer of hydrogen atoms between the substrate and the graphene and thereby decouples the graphene layer from the underlying silicon carbide, proved to be a better choice than the more standard as-grown graphene. Robinson says, “In general QFEG is more interesting, and from a device point of view, it’s critical.”

To see if quasi-free-standing graphene was a suitable template for the growth of other artificially stacked atomic layers, the team synthesized two other van der Waals solids: tungsten diselenide, and hexagonal boron nitride. (van der Waals solids have strong in-plane bonding but weak interlayer bonding.) They determined that epitaxial graphene was “an excellent candidate for building large-area vdW solids that will have extraordinary properties and performances.”

Industry has already shown strong interest in 2D layered materials for RF applications, low-power and low-cost semiconductors, and for displays on flexible substrates. “This is the first step,” Robinson says. “To truly control properties we will need to look at a variety of these systems that should turn out to have entirely new properties when stacked together.”

Contributors to the ACS Nano article, “Direct Synthesis of van der Waals Solids,” are lead author Yu-Chuan Lin, a Ph.D. candidate in Robinson’s group, Nestor Perea-Lopez, Jie Li, Zhong Lin, Chia Hui Lee, Lazaro Calderon, Paul N. Brown, Michael S. Bresnehan, Theresa Mayer, Mauricio Terrones, and Joshua Robinson, all of Penn State, and Ning Lu, Xin Peng, Ce Sun, and Moon J. Kim, all of University of Texas at Dallas. The work at Penn State and UT Dallas was supported by the Center for Low Energy Systems Technology (LEAST), and by the National Nanotechnology Infrastructure Network at Penn State. Contact Joshua Robinson at jar403@psu.edu. For more information on 2D materials, visit the Penn State Center for 2-Dimensional and Layered Materials at mri.psu.edu/centers/2dlm/. (DOI: 10.1021/nn5003858)

Yu-Chuan Lin | newswise

Further reports about: ACS Atomic Layer MoS2 Nano carbide graphene materials photodetector

More articles from Materials Sciences:

nachricht 3-D printing produces cartilage from strands of bioink
27.06.2016 | Penn State

nachricht Nanoscientists develop the 'ultimate discovery tool'
24.06.2016 | Northwestern University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Optical lenses, hardly larger than a human hair

3D printing enables the smalles complex micro-objectives

3D printing revolutionized the manufacturing of complex shapes in the last few years. Using additive depositing of materials, where individual dots or lines...

Im Focus: Flexible OLED applications arrive

R2D2, a joint project to analyze and development high-TRL processes and technologies for manufacture of flexible organic light-emitting diodes (OLEDs) funded by the German Federal Ministry of Education and Research (BMBF) has been successfully completed.

In contrast to point light sources like LEDs made of inorganic semiconductor crystals, organic light-emitting diodes (OLEDs) are light-emitting surfaces. Their...

Im Focus: Unexpected flexibility found in odorant molecules

High resolution rotational spectroscopy reveals an unprecedented number of conformations of an odorant molecule – a new world record!

In a recent publication in the journal Physical Chemistry Chemical Physics, researchers from the Max Planck Institute for the Structure and Dynamics of Matter...

Im Focus: 3-D printing produces cartilage from strands of bioink

Strands of cow cartilage substitute for ink in a 3D bioprinting process that may one day create cartilage patches for worn out joints, according to a team of engineers. "Our goal is to create tissue that can be used to replace large amounts of worn out tissue or design patches," said Ibrahim T. Ozbolat, associate professor of engineering science and mechanics. "Those who have osteoarthritis in their joints suffer a lot. We need a new alternative treatment for this."

Cartilage is a good tissue to target for scale-up bioprinting because it is made up of only one cell type and has no blood vessels within the tissue. It is...

Im Focus: First experimental quantum simulation of particle physics phenomena

Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.

Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Conference ‘GEO BON’ Wants to Close Knowledge Gaps in Global Biodiversity

28.06.2016 | Event News

ERES 2016: The largest conference in the European real estate industry

09.06.2016 | Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

 
Latest News

Building a better battery

29.06.2016 | Life Sciences

New way out: Researchers show how stem cells exit bloodstream

29.06.2016 | Life Sciences

Crucial peatlands carbon-sink vulnerable to rising sea levels

29.06.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>