Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Scientists craft atomically seamless, thinnest-possible semiconductor junctions

U of Washington

As seen under an optical microscope, the heterostructures have a triangular shape. The two different monolayer semiconductors can be recognized through their different colors.
U of Washington

As seen under an optical microscope, the heterostructures have a triangular shape. The two different monolayer semiconductors can be recognized through their different colors.

Abstract:
Scientists have developed what they believe is the thinnest-possible semiconductor, a new class of nanoscale materials made in sheets only three atoms thick.

Scientists craft atomically seamless, thinnest-possible semiconductor junctions

Seattle, WA | Posted on August 26th, 2014

The University of Washington researchers have demonstrated that two of these single-layer semiconductor materials can be connected in an atomically seamless fashion known as a heterojunction. This result could be the basis for next-generation flexible and transparent computing, better light-emitting diodes, or LEDs, and solar technologies.

"Heterojunctions are fundamental elements of electronic and photonic devices," said senior author Xiaodong Xu, a UW assistant professor of materials science and engineering and of physics. "Our experimental demonstration of such junctions between two-dimensional materials should enable new kinds of transistors, LEDs, nanolasers, and solar cells to be developed for highly integrated electronic and optical circuits within a single atomic plane."

The research was published online this week in Nature Materials.

The researchers discovered that two flat semiconductor materials can be connected edge-to-edge with crystalline perfection. They worked with two single-layer, or monolayer, materials - molybdenum diselenide and tungsten diselenide - that have very similar structures, which was key to creating the composite two-dimensional semiconductor.

Collaborators from the electron microscopy center at the University of Warwick in England found that all the atoms in both materials formed a single honeycomb lattice structure, without any distortions or discontinuities. This provides the strongest possible link between two single-layer materials, necessary for flexible devices. Within the same family of materials it is feasible that researchers could bond other pairs together in the same way.

The researchers created the junctions in a small furnace at the UW. First, they inserted a powder mixture of the two materials into a chamber heated to 900 degrees Celsius (1,652 F). Hydrogen gas was then passed through the chamber and the evaporated atoms from one of the materials were carried toward a cooler region of the tube and deposited as single-layer crystals in the shape of triangles.

After a while, evaporated atoms from the second material then attached to the edges of the triangle to create a seamless semiconducting heterojunction.

"This is a scalable technique," said Sanfeng Wu, a UW doctoral student in physics and one of the lead authors. "Because the materials have different properties, they evaporate and separate at different times automatically. The second material forms around the first triangle that just previously formed. That's why these lattices are so beautifully connected."

With a larger furnace, it would be possible to mass-produce sheets of these semiconductor heterostructures, the researchers said. On a small scale, it takes about five minutes to grow the crystals, with up to two hours of heating and cooling time.

"We are very excited about the new science and engineering opportunities provided by these novel structures," said senior author David Cobden, a UW professor of physics. "In the future, combinations of two-dimensional materials may be integrated together in this way to form all kinds of interesting electronic structures such as in-plane quantum wells and quantum wires, superlattices, fully functioning transistors, and even complete electronic circuits."

The researchers have already demonstrated that the junction interacts with light much more strongly than the rest of the monolayer, which is encouraging for optoelectric and photonic applications like solar cells.

Other co-authors are Chunming Huang and Pasqual Rivera of UW physics; Ana Sanchez, Richard Beanland and Jonathan Peters at the University of Warwick; Jason Ross of UW materials science and engineering; and Wang Yao, a theoretical physicist of the University of Hong Kong.

This research was funded by the U.S. Department of Energy, the UW's Clean Energy Institute, the Research Grant Council of Hong Kong, the University Grants Committee of Hong Kong, the Croucher Foundation, the Science City Research Alliance and the Higher Education Funding Council for England's Strategic Development Fund.

Grant numbers: U.S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division (DE-SC0008145) (DE-SC0002197).

####

For more information, please click here

Contacts:
Michelle Ma

206-543-2580

Sanfeng Wu

Copyright © University of Washington

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

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Imaging

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

First direct imaging of small noble gas clusters at room temperature: Novel opportunities in quantum technology and condensed matter physics opened by noble gas atoms confined between graphene layers January 12th, 2024

The USTC realizes In situ electron paramagnetic resonance spectroscopy using single nanodiamond sensors November 3rd, 2023

Observation of left and right at nanoscale with optical force October 6th, 2023

Govt.-Legislation/Regulation/Funding/Policy

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024

Chip Technology

New chip opens door to AI computing at light speed February 16th, 2024

HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024

Electrons screen against conductivity-killer in organic semiconductors: The discovery is the first step towards creating effective organic semiconductors, which use significantly less water and energy, and produce far less waste than their inorganic counterparts February 16th, 2024

NRL discovers two-dimensional waveguides February 16th, 2024

Discoveries

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Announcements

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

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

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Tools

First direct imaging of small noble gas clusters at room temperature: Novel opportunities in quantum technology and condensed matter physics opened by noble gas atoms confined between graphene layers January 12th, 2024

New laser setup probes metamaterial structures with ultrafast pulses: The technique could speed up the development of acoustic lenses, impact-resistant films, and other futuristic materials November 17th, 2023

Ferroelectrically modulate the Fermi level of graphene oxide to enhance SERS response November 3rd, 2023

The USTC realizes In situ electron paramagnetic resonance spectroscopy using single nanodiamond sensors November 3rd, 2023

Research partnerships

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

'Sudden death' of quantum fluctuations defies current theories of superconductivity: Study challenges the conventional wisdom of superconducting quantum transitions January 12th, 2024

Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project