Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Scalable CVD process for making 2-D molybdenum diselenide: Rice, NTU scientists unveil CVD production for coveted 2-D semiconductor

This image from a scanning transmission electron microscope shows the individual atoms in a two-dimensional sheet of molybdenum diselenide.
CREDIT: E. Ringe/Rice University
This image from a scanning transmission electron microscope shows the individual atoms in a two-dimensional sheet of molybdenum diselenide.

CREDIT: E. Ringe/Rice University

Abstract:
Nanoengineering researchers at Rice University and Nanyang Technological University in Singapore have unveiled a potentially scalable method for making one-atom-thick layers of molybdenum diselenide -- a highly sought semiconductor that is similar to graphene but has better properties for making certain electronic devices like switchable transistors and light-emitting diodes.

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

Houston, TX | Posted on April 8th, 2014

The method for making two-dimensional molybdenum diselenide uses a technique known as chemical vapor deposition (CVD) and is described online in a new paper in the American Chemical Society journal ACS Nano. The finding is significant because CVD is widely used by the semiconductor and materials industries to make thin films of silicon, carbon fibers and other materials.

"This new method will allow us to exploit the properties of molybdenum diselenide in a number of applications," said study leader Pulickel Ajayan, chair of Rice's Department of Materials Science and NanoEngineering. "Unlike graphene, which can now easily be made in large sheets, many interesting 2-D materials remain difficult to synthesize. Now that we have a stable, efficient way to produce 2-D molybdenum diselenide, we are planning to expand this robust procedure to other 2-D materials."

In the Rice study, Ajayan and colleagues tested their atomically thin layers of molybdenum diselenide by building a field effect transistor (FET), a commonly used device in the microelectronic industry. Tests of the FET found the electronic properties of the molybdenum diselenide layers were significantly better than those of molybdenum disulfide; the latter is a similar material that has been more extensively studied because it was easier to fabricate. For example, the FET tests found that the electron mobility of Rice's molybdenum diselenide was higher than that of CVD-grown, molybdenum disulfide.

In solid-state physics, electron mobility refers to how quickly electrons pass through a metal or semiconductor in the presence of an electric field. Materials with high electron mobility are often preferred to reduce power consumption and heating in microelectronic devices.

"Being able to make 2-D materials in a controlled fashion really will make an impact on our understanding and use of their fascinating properties," said study co-author Emilie Ringe, assistant professor of materials science and nanoengineering and of chemistry at Rice. "Characterizing both the structure and function of a material, as we have done in this paper, is critical to such advances."

Molybdenum diselenide and molybdenum disulfide each belong to a class of materials known as transition metal dichalcogenides; TMDCs are so named because they consist of two elements, a transition metal like molybdenum or tungsten and a "chalcogen" like sulfur, selenium or tellurium.

TMDCs have attracted intense interest from materials scientists because they have an atomic structure similar to graphene, the pure carbon wonder materials that attracted the 2010 Nobel Prize in physics. Graphene and similar materials are often referred to as two-dimensional because they are only one atom thick. Graphene has extraordinary electronic properties. For example, its electron mobility is tens of thousands of times greater than that of TMDCs.

However, two-dimensional TMDCs like molybdenum diselenide have attracted intense interest because their electronic properties are complementary to graphene. For example, pure graphene has no bandgap -- a useful electronic property that engineers can exploit to make FETs that are easily switched on and off.

As with many nanomaterials, scientists have found that the physical properties of TMDCs change markedly when the material has nanoscale properties. For example, a slab of molybdenum diselenide that is even a micron thick has an "indirect" bandgap while a two-dimensional sheet of molybdenum diselenide has a "direct" bandgap. The difference is important for electronics because direct-bandgap materials can be used to make switchable transistors and sensitive photodetectors.

"One of the driving forces in Rice's Department of Materials Science and NanoEngineering is the close collaborations that develop between the people who are focused on synthesis and those of us involved with characterization," said Ringe, who joined Rice's faculty in January. "We hope this will be the beginning of a series of new protocols to reliably synthesize a variety of 2-D materials."

The research was supported by the Army Research Office, the Semiconductor Research Corporation's FAME Center, the Office of Naval Research and Singapore's MOE Academic Research Fund.

Additional study co-authors include Xingli Wang, Yongji Gong, Gang Shi, Kunttal Keyshar, Gonglan Ye, Robert Vajtai and Jun Lou, all of Rice, and Wai Leong Chow, Zheng Liu and Beng Kang Tay, all of Nanyang Technological University.

####

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 3,920 undergraduates and 2,567 graduate students, Rice's undergraduate student-to-faculty ratio is 6.3-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.

For more information, please click here

Contacts:
Jade Boyd
713-348-6778

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

A copy of the ACS Nano paper is available at:

More information about Rice's Department of Materials Science and NanoEngineering:

Related News Press

News and information

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Superfast light source made from artificial atom April 28th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

Display technology/LEDs/SS Lighting/OLEDs

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Manipulating light inside opaque layers April 24th, 2016

Graphene/ Graphite

University of Illinois researchers create 1-step graphene patterning method April 27th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

Electrically Conductive Graphene Ink Enables Printing of Biosensors April 23rd, 2016

Thin films

Flipping a chemical switch helps perovskite solar cells beat the heat April 26th, 2016

Thin-film solar cells: How defects appear and disappear in CIGSe cells: Concentration of copper plays a crucial role April 23rd, 2016

Govt.-Legislation/Regulation/Funding/Policy

Nanoparticles hold promise as double-edged sword against genital herpes April 28th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

NREL theory establishes a path to high-performance 2-D semiconductor devices April 27th, 2016

Researchers create artificial protein to control assembly of buckyballs April 27th, 2016

Chip Technology

Researchers create a first frequency comb of time-bin entangled qubits: Discovery is a significant step toward multi-channel quantum communication and higher capacity quantum computers April 28th, 2016

University of Illinois researchers create 1-step graphene patterning method April 27th, 2016

NREL theory establishes a path to high-performance 2-D semiconductor devices April 27th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

Discoveries

Nanoparticles hold promise as double-edged sword against genital herpes April 28th, 2016

Researchers create a first frequency comb of time-bin entangled qubits: Discovery is a significant step toward multi-channel quantum communication and higher capacity quantum computers April 28th, 2016

Superfast light source made from artificial atom April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

Announcements

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Superfast light source made from artificial atom April 28th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

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

Nanoparticles hold promise as double-edged sword against genital herpes April 28th, 2016

Researchers create a first frequency comb of time-bin entangled qubits: Discovery is a significant step toward multi-channel quantum communication and higher capacity quantum computers April 28th, 2016

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Superfast light source made from artificial atom April 28th, 2016

Military

Nanograft seeded with 3 cell types promotes blood vessel formation to speed wound healing April 27th, 2016

The light stuff: A brand-new way to produce electron spin currents - Colorado State University physicists are the first to demonstrate using non-polarized light to produce a spin voltage in a metal April 26th, 2016

NRL reveals novel uniform coating process of p-ALD April 21st, 2016

Team builds first quantum cascade laser on silicon: Eliminates the need for an external light source for mid-infrared silicon photonic devices or photonic circuits April 21st, 2016

Research partnerships

Nanoparticles hold promise as double-edged sword against genital herpes April 28th, 2016

Researchers create a first frequency comb of time-bin entangled qubits: Discovery is a significant step toward multi-channel quantum communication and higher capacity quantum computers April 28th, 2016

Nanograft seeded with 3 cell types promotes blood vessel formation to speed wound healing April 27th, 2016

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

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







Car Brands
Buy website traffic