Nav: Home

Discovery in gallium nitride a key enabler of energy efficient electronics

September 26, 2019

ITHACA, N.Y. - Gallium nitride, a semiconductor that revolutionized energy-efficient LED lighting, could also transform electronics and wireless communication, thanks to a discovery made by Cornell researchers.

Their paper, "A Polarization-Induced 2D Hole Gas in Undoped Gallium Nitride Quantum Wells," was published Sept. 26 in Science.

Silicon has long been the king of semiconductors, but it has had a little help. The pure material is often augmented, or "doped," with impurities like phosphorus or boron to enhance current flow by providing negative charges (electrons) or positive charges ("holes," the absence of electrons) as needed.

In recent years, a newer, sturdier family of lab-grown compound semiconductor materials has emerged: group III-nitrides. Gallium nitride (GaN) and aluminum nitride (AlN) and their alloys have a wider bandgap, allowing them to withstand greater voltages and higher frequencies for faster, more efficient energy transmission.

"Silicon is very good at switching off and on and controlling electrical energy flow, but when you take it to high voltages it doesn't operate very well because silicon has a weak electric strength, whereas GaN can sustain much higher electric fields," said co-senior author Debdeep Jena, professor of electrical and computer engineering and of materials science and engineering "If you're doing very large amounts of energy conversion, then wide-bandgap semiconductors such as GaN and silicon carbide are the solutions."

Rather than using impurities, Ph.D. student Reet Chaudhuri, the paper's lead author, stacked a thin GaN crystal layer - called a quantum well - atop an AlN crystal, and the difference in their crystal structures was found to generate a high density of mobile holes. Compared with magnesium-doping, the researchers discovered that the resulting 2D hole gas makes the GaN structures almost 10 times more conductive.

Using the new material structure created by Chaudhuri, co-author and Ph.D. student Samuel James Bader recently demonstrated some of the most efficient p-type GaN transistors in a collaborative project with Intel. Now that the team has the capability to make hole-channel transistors - which are called p-type - they plan to pair them with n-type transistors to form more complex circuits, opening up new possibilities in high-power switching, 5G cellular technology and energy efficient electronics, including phone and laptop chargers.

"It's very difficult to simultaneously achieve n-type and p-type in a wide bandgap semiconductor. Right now, silicon carbide is the only other one that has both besides GaN. But the mobile electrons in silicon carbide are more sluggish than those in GaN," said co-senior author Huili Grace Xing, professor of electrical and computer engineering and of materials science and engineering. "Using these complementary operations enabled by both n-type and p-type devices, much more energy efficient architecture can be built."

Another advantage of the 2D hole gas is that its conductivity improves as the temperature is lowered, meaning that researchers will now be able to study fundamental GaN properties in ways that haven't been previously possible. Equally important is its ability to retain energy that would otherwise be lost in less efficient power systems.
-end-
A patent application has been filed through the Center for Technology Licensing for the discovery. PlantPlant Co The research was supported in part by Intel, the Air Force Office of Scientific Research, the National Science Foundation and the Cornell Center for Materials Research.

For more information, see this Cornell Chronicle story. Cornell University has dedicated television and audio studios available for media interviews supporting full HD, ISDN and web-based platforms.

Cornell University

Related Semiconductor Articles:

Clemson researcher's novel MOF is potential next-gen semiconductor
Clemson professor Sourav Saha demonstrated a novel double-helical metal organic framework architecture in a partially oxidized form that conducts electricity, potentially making it a next-generation semiconductor.
A gold butterfly can make its own semiconductor skin
A nanoscale gold butterfly provides a more precise route for growing/synthesizing nanosized semiconductors that can be used in nano-lasers and other applications.
Scientists pioneer new generation of semiconductor neutron detector
In a new study, scientists have developed a new type of semiconductor neutron detector that boosts detection rates by reducing the number of steps involved in neutron capture and transduction.
Scientists see defects in potential new semiconductor
A research team has reported seeing, for the first time, atomic scale defects that dictate the properties of a new and powerful semiconductor.
Bending an organic semiconductor can boost electrical flow
Slightly bending semiconductors made of organic materials can roughly double the speed of electricity flowing through them and could benefit next-generation electronics such as sensors and solar cells, according to Rutgers-led research.
Paving a way to achieve unexplored semiconductor nanostructures
A research team of Ehime University paved a way to achieve unexplored III-V semiconductor nanostructures.
Clarification of a new synthesis mechanism of semiconductor atomic sheet
Researchers at Tohoku University in Japan succeeded in clarifying a new synthesis mechanism regarding transition metal dichalcogenides (TMD), which are semiconductor atomic sheets having thickness in atomic order.
Future of portable electronics -- Novel organic semiconductor with exciting properties
Organic semiconductors have advantages over inorganic semiconductors in several areas.
A new method for quantifying crystal semiconductor efficiency
Japanese scientists have found a new way to successfully detect the efficiency of crystal semiconductors.
X-rays reveal monolayer phase in organic semiconductor
An international team of researchers has investigated how the electrical properties of dihexyl-quarterthiophene thin films depend on their structure.
More Semiconductor News and Semiconductor Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Space
One of the most consistent questions we get at the show is from parents who want to know which episodes are kid-friendly and which aren't. So today, we're releasing a separate feed, Radiolab for Kids. To kick it off, we're rerunning an all-time favorite episode: Space. In the 60's, space exploration was an American obsession. This hour, we chart the path from romance to increasing cynicism. We begin with Ann Druyan, widow of Carl Sagan, with a story about the Voyager expedition, true love, and a golden record that travels through space. And astrophysicist Neil de Grasse Tyson explains the Coepernican Principle, and just how insignificant we are. Support Radiolab today at Radiolab.org/donate.