Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Getting electrons to move in a semiconductor: Gallium oxide shows high electron mobility, making it promising for better and cheaper devices

Schematic stack and the scanning electron microscopic image of the β-(AlxGa1-x)2O3/Ga2O3 modulation-doped field effect transistor.
CREDIT
Choong Hee Lee and Yuewei Zhang
Schematic stack and the scanning electron microscopic image of the β-(AlxGa1-x)2O3/Ga2O3 modulation-doped field effect transistor. CREDIT Choong Hee Lee and Yuewei Zhang

Abstract:
The next generation of energy-efficient power electronics, high-frequency communication systems, and solid-state lighting rely on materials known as wide bandgap semiconductors. Circuits based on these materials can operate at much higher power densities and with lower power losses than silicon-based circuits. These materials have enabled a revolution in LED lighting, which led to the 2014 Nobel Prize in physics.

Getting electrons to move in a semiconductor: Gallium oxide shows high electron mobility, making it promising for better and cheaper devices

Washington, DC | Posted on April 24th, 2018

In new experiments reported in Applied Physics Letters, from AIP Publishing, researchers have shown that a wide-bandgap semiconductor called gallium oxide (Ga2O3) can be engineered into nanometer-scale structures that allow electrons to move much faster within the crystal structure. With electrons that move with such ease, Ga2O3 could be a promising material for applications such as high-frequency communication systems and energy-efficient power electronics.

"Gallium oxide has the potential to enable transistors that would surpass current technology," said Siddharth Rajan of Ohio State University, who led the research.

Because Ga2O3 has one of the largest bandgaps (the energy needed to excite an electron so that it's conductive) of the wide bandgap materials being developed as alternatives to silicon, it's especially useful for high-power and high-frequency devices. It's also unique among wide bandgap semiconductors in that it can be produced directly from its molten form, which enables large-scale manufacturing of high-quality crystals.

For use in electronic devices, the electrons in the material must be able to move easily under an electric field, a property called high electron mobility. "That's a key parameter for any device," Rajan said. Normally, to populate a semiconductor with electrons, the material is doped with other elements. The problem, however, is that the dopants also scatter electrons, limiting the electron mobility of the material.

To solve this problem, the researchers used a technique known as modulation doping. The approach was first developed in 1979 by Takashi Mimura to create a gallium arsenide high-electron mobility transistor, which won the Kyoto Prize in 2017. While it is now a commonly used technique to achieve high mobility, its application to Ga2O3 is something new.

In their work, the researchers created a so-called semiconductor heterostructure, creating an atomically perfect interface between Ga2O3 and its alloy with aluminum, aluminum gallium oxide -- two semiconductors with the same crystal structure but different energy gaps. A few nanometers away from the interface, embedded inside the aluminum gallium oxide, is a sheet of electron-donating impurities only a few atoms thick. The donated electrons transfer into the Ga2O3, forming a 2-D electron gas. But because the electrons are now also separated from the dopants (hence the term modulation doping) in the aluminum gallium oxide by a few nanometers, they scatter much less and remain highly mobile.

Using this technique, the researchers reached record mobilities. The researchers were also able to observe Shubnikov-de Haas oscillations, a quantum phenomenon in which increasing the strength of an external magnetic field causes the resistance of the material to oscillate. These oscillations confirm formation of the high mobility 2-D electron gas and allow the researchers to measure critical material properties.

Rajan explained that such modulation-doped structures could lead to a new class of quantum structures and electronics that harnesses the potential of Ga2O3.

####

About American Institute of Physics
Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology. See http://apl.aip.org .

For more information, please click here

Contacts:
Julia Majors

301-209-3090

Copyright © American Institute of Physics

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

The article, "Demonstration of high mobility and quantum transport in modulation-doped β-(AlxGa1-x)2O3/Ga2O3 heterostructures," is authored by Yuewei Zhang, Adam Neal, Zhanbo Xia, Chandan Joishi, Yuanhua Zheng, Sanyam Bajaj, Mark Brenner, Shin Mou, Donald Dorsey, Kelson Chabak, Gregg Jessen, Jinwoo Hwang, Joseph Heremans and Siddarth Rajan. The article will appear in Applied Physics Letters April 24, 2018 (DOI: 10.1063/1.5025704). After that date, it can be accessed at:

Related News Press

News and information

MTU engineers examine lithium battery defects January 28th, 2020

Extraction of lithium from its largest source, i.e. seawater, by nanostructured membranes January 27th, 2020

SUNY Poly Professor Partners with Leading Institutions on NSF Award for Quantum Information Science Research: SUNY Poly Research Builds Upon Recent Quantum-related Research Initiatives and Workshops January 27th, 2020

What if the Universe has no end? The Big Bang is widely accepted as being the beginning of everything we see around us, but other theories that are gathering support among scientists are suggesting otherwise January 25th, 2020

A consensus statement establishes the protocols to study stability of perovskite photovoltaic devices January 24th, 2020

Hardware

SUNY Poly Professor Partners with Leading Institutions on NSF Award for Quantum Information Science Research: SUNY Poly Research Builds Upon Recent Quantum-related Research Initiatives and Workshops January 27th, 2020

Display technology/LEDs/SS Lighting/OLEDs

Nano-thin flexible touchscreens could be printed like newspaper: New touch-responsive technology is 100 times thinner than existing touchscreen materials and so pliable it can be rolled up like a tube January 24th, 2020

Let the europium shine brighter January 21st, 2020

Scientists create thin films with tantalizing electronic properties: As predicted by theorists, experiments show that barium zirconium sulfide thin films hold great promise for solar cells, LEDs December 27th, 2019

2 Dimensional Materials

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Generation and Manipulation of spin currents for advanced electronic devices January 9th, 2020

NUS scientists create world’s first monolayer amorphous film January 9th, 2020

Possible Futures

MTU engineers examine lithium battery defects January 28th, 2020

SUNY Poly Professor Partners with Leading Institutions on NSF Award for Quantum Information Science Research: SUNY Poly Research Builds Upon Recent Quantum-related Research Initiatives and Workshops January 27th, 2020

What if the Universe has no end? The Big Bang is widely accepted as being the beginning of everything we see around us, but other theories that are gathering support among scientists are suggesting otherwise January 25th, 2020

Nano-thin flexible touchscreens could be printed like newspaper: New touch-responsive technology is 100 times thinner than existing touchscreen materials and so pliable it can be rolled up like a tube January 24th, 2020

Chip Technology

Toward safer disposal of printed circuit boards January 16th, 2020

Generation and Manipulation of spin currents for advanced electronic devices January 9th, 2020

NUS scientists create world’s first monolayer amorphous film January 9th, 2020

Onto Innovation to Present at the 22nd Annual Needham Growth Conference January 3rd, 2020

Nanoelectronics

FEFU scientists participate in development of ceramic materials that are IR-transparent December 27th, 2019

In leap for quantum computing, silicon quantum bits establish a long-distance relationship: Princeton scientists demonstrate that two silicon quantum bits can communicate across relatively long distances in a turning point for the technology December 27th, 2019

Saving Moore’s Law: Electrical and computer engineering researchers propose 3D integration with 2D materials December 27th, 2019

New laser technique images quantum world in a trillionth of a second: Technique captures a process that commonly causes electrical resistance in materials while, in others, can cause the absence of resistance, or superconductivity December 13th, 2019

Discoveries

Extraction of lithium from its largest source, i.e. seawater, by nanostructured membranes January 27th, 2020

Quantum physics: On the way to quantum networks January 24th, 2020

Nano-thin flexible touchscreens could be printed like newspaper: New touch-responsive technology is 100 times thinner than existing touchscreen materials and so pliable it can be rolled up like a tube January 24th, 2020

Old Molecule, New Tricks: Chemistry professors develop an electrochemical method for extracting uranium, and potentially other metal ions, from solution January 24th, 2020

Materials/Metamaterials

MTU engineers examine lithium battery defects January 28th, 2020

Researchers gain control over internal structure of self-assembled composite materials January 16th, 2020

Buckyballs release electron-positron pairs in forward directions: Theoretical calculations reveal that when impacted by positrons of particular energies, spherical nanoparticles release unstable electron-positron pairs, with signals dominating in the same direction as the incomin December 27th, 2019

FEFU scientists participate in development of ceramic materials that are IR-transparent December 27th, 2019

Announcements

MTU engineers examine lithium battery defects January 28th, 2020

Extraction of lithium from its largest source, i.e. seawater, by nanostructured membranes January 27th, 2020

SUNY Poly Professor Partners with Leading Institutions on NSF Award for Quantum Information Science Research: SUNY Poly Research Builds Upon Recent Quantum-related Research Initiatives and Workshops January 27th, 2020

American Chemical Society names Philip Proteau as new editor-in-chief of the Journal of Natural Products January 24th, 2020

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

MTU engineers examine lithium battery defects January 28th, 2020

Extraction of lithium from its largest source, i.e. seawater, by nanostructured membranes January 27th, 2020

What if the Universe has no end? The Big Bang is widely accepted as being the beginning of everything we see around us, but other theories that are gathering support among scientists are suggesting otherwise January 25th, 2020

A consensus statement establishes the protocols to study stability of perovskite photovoltaic devices January 24th, 2020

Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records

MTU engineers examine lithium battery defects January 28th, 2020

Nano-thin flexible touchscreens could be printed like newspaper: New touch-responsive technology is 100 times thinner than existing touchscreen materials and so pliable it can be rolled up like a tube January 24th, 2020

Pretty with a twist: Complex porous, chiral nano-patterns arise from a simple linear building block January 16th, 2020

Gasification goes green: Rice's low-temp photocatalyst could slash the carbon footprint for syngas January 10th, 2020

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