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 Controlling phase changes in solids
29.07.2015 | ICFO-The Institute of Photonic Sciences

nachricht Smart Hydrogel Coating Creates “Stick-slip” Control of Capillary Action
28.07.2015 | Georgia Institute of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

Im Focus: Simulations lead to design of near-frictionless material

Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.

While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...

Im Focus: NASA satellite camera provides 'EPIC' view of Earth

A NASA camera on the Deep Space Climate Observatory (DSCOVR) satellite has returned its first view of the entire sunlit side of Earth from one million miles away.

The color images of Earth from NASA's Earth Polychromatic Imaging Camera (EPIC) are generated by combining three separate images to create a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

A New Litmus Test for Chaos?

29.07.2015 | Physics and Astronomy

New Computer Model Could Explain how Simple Molecules Took First Step Toward Life

29.07.2015 | Life Sciences

New ERC calls published under Horizon 2020

29.07.2015 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>