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 |
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.
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.
Related Links |
Related News Press |
News and information
Single quantum bit achieves complex systems modeling June 9th, 2023
Quantum materials: Electron spin measured for the first time June 9th, 2023
Liquid metal sticks to surfaces without a binding agent June 9th, 2023
Graphene-based Carbocatalysts: Synthesis, Properties, and Applications—Beyond Boundaries June 9th, 2023
2 Dimensional Materials
Graphene-based Carbocatalysts: Synthesis, Properties, and Applications—Beyond Boundaries June 9th, 2023
HKUMed invents a novel two-dimensional (2D) ultrasound-responsive antibacterial nano-sheets to effectively address bone tissue infection March 24th, 2023
Display technology/LEDs/SS Lighting/OLEDs
Novel design perovskite electrochemical cell for light-emission and light-detection May 12th, 2023
A universal HCl-assistant powder-to-powder strategy for preparing lead-free perovskites March 24th, 2023
3D-printed decoder, AI-enabled image compression could enable higher-res displays December 9th, 2022
Hardware
A Carbon Nanotube Microprocessor Mature Enough to Say Hello: Three new breakthroughs make commercial nanotube processors possible March 2nd, 2020
Powering the future: Smallest all-digital circuit opens doors to 5 nm next-gen semiconductor February 11th, 2020
Do you Kyoto? World-leading companies share their approaches to environmentally friendly business at NAUM’19 October 14th, 2019
Possible Futures
USTC enhances fluorescence brightness of single silicon carbide spin color centers June 9th, 2023
Single quantum bit achieves complex systems modeling June 9th, 2023
Advances in nanotechnology application in biosafety materials A crucial response to COVID-19 pandemic June 9th, 2023
Researchers discover materials exhibiting huge magnetoresistance June 9th, 2023
Chip Technology
USTC enhances fluorescence brightness of single silicon carbide spin color centers June 9th, 2023
Researchers discover materials exhibiting huge magnetoresistance June 9th, 2023
Breaking through the limits of stretchable semiconductors with molecular brakes that harness light June 9th, 2023
Laser direct writing of Ga2O3/liquid metal-based flexible humidity sensors May 12th, 2023
Nanoelectronics
Key element for a scalable quantum computer: Physicists from Forschungszentrum Jülich and RWTH Aachen University demonstrate electron transport on a quantum chip September 23rd, 2022
Reduced power consumption in semiconductor devices September 23rd, 2022
Atomic level deposition to extend Moore’s law and beyond July 15th, 2022
Controlled synthesis of crystal flakes paves path for advanced future electronics June 17th, 2022
Discoveries
When all details matter -- Heat transport in energy materials June 9th, 2023
Advances in nanotechnology application in biosafety materials A crucial response to COVID-19 pandemic June 9th, 2023
Researchers discover materials exhibiting huge magnetoresistance June 9th, 2023
Materials/Metamaterials/Magnetoresistance
Nanobiotechnology: How Nanomaterials Can Solve Biological and Medical Problems April 14th, 2023
New Developments in Biosensor Technology: From Nanomaterials to Cancer Detection April 14th, 2023
Diamond cut precision: University of Illinois to develop diamond sensors for neutron experiment and quantum information science April 14th, 2023
Bilayer PET/PVDF substrate-reinforced solid polymer electrolyte improves solid-state lithium metal battery performance March 24th, 2023
Announcements
Liquid metal sticks to surfaces without a binding agent June 9th, 2023
Graphene-based Carbocatalysts: Synthesis, Properties, and Applications—Beyond Boundaries June 9th, 2023
When all details matter -- Heat transport in energy materials June 9th, 2023
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
USTC enhances fluorescence brightness of single silicon carbide spin color centers June 9th, 2023
Single quantum bit achieves complex systems modeling June 9th, 2023
Advances in nanotechnology application in biosafety materials A crucial response to COVID-19 pandemic June 9th, 2023
Researchers discover materials exhibiting huge magnetoresistance June 9th, 2023
Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records
Optical switching at record speeds opens door for ultrafast, light-based electronics and computers: March 24th, 2023
Semiconductor lattice marries electrons and magnetic moments March 24th, 2023
![]() |
||
![]() |
||
The latest news from around the world, FREE | ||
![]() |
![]() |
||
Premium Products | ||
![]() |
||
Only the news you want to read!
Learn More |
||
![]() |
||
Full-service, expert consulting
Learn More |
||
![]() |