Nav: Home

Silicon as a semiconductor: Silicon carbide would be much more efficient

September 05, 2019

In power electronics, semiconductors are based on the element silicon - but the energy efficiency of silicon carbide would be much higher. Physicists of the University of Basel, the Paul Scherrer Institute and ABB explain what exactly is preventing the use of this combination of silicon and carbon in the scientific journal Applied Physics Letters.

Energy consumption is growing across the globe; electric power is being relied upon more and more, and sustainable energy supplies such as wind and solar power are becoming increasingly important. Electric power, however, is often generated a long distance away from the consumer. Efficient distribution and transport systems are thus just as crucial as transformer stations and power converters that turn the generated direct current into alternating current.

Huge savings are possible

Modern power electronics must be able to handle large currents and high voltages. Current transistors made of semiconductor materials for field-effect transistors are now mainly based on silicon technology. Significant physical and chemical advantages, however, arise from the use of SiC over silicon: in addition to a much higher heat resistance, this material provides significantly better energy efficiency, which could lead to massive savings.

It is known that these advantages are significantly compromised by defects at the interface between silicon carbide and the insulating material silicon dioxide. This damage is based on tiny, irregular clusters of carbon rings bound in the crystal lattice, as experimentally demonstrated by researchers led by Professor Thomas Jung at the Swiss Nanoscience Institute and Department of Physics from the University of Basel and the Paul Scherrer Institute. Using atomic force microscope analysis and Raman spectroscopy, they showed that the defects are generated in the vicinity of the interface by the oxidation process.

Experimentally confirmed

The interfering carbon clusters, which are only a few nanometers in size, are formed during the oxidation process of silicon carbide to silicon dioxide under high temperatures. "If we change certain parameters during oxidation, we can influence the occurrence of the defects," says doctoral student Dipanwita Dutta. For example, a nitrous oxide atmosphere in the heating process leads to significantly fewer carbon clusters.

The experimental results were confirmed by the team led by Professor Stefan Gödecker at the Department of Physics and Swiss Nanoscience Institute from the University of Basel. Computer simulations confirmed the structural and chemical changes induced by graphitic carbon atoms as observed experimentally. Beyond experiments, atomistic insight has been gained in the generation of the defects and their impact on the electron flow in the semiconductor material.

Better use of electricity

"Our studies provide important insight to drive the onward development of field-effect transistors based on silicon carbide. Therefore we expect to provide a significant contribution to the more effective use of electrical power," comments Jung. The work was initiated as part of the Nano Argovia program for applied research projects.
-end-


University of Basel

Related Carbon Articles:

Carbon storage from the lab
Researchers at the University of Freiburg established the world's largest collection of moss species for the peat industry and science
Carbon-carbon covalent bonds far more flexible than presumed
A Hokkaido University research group has successfully demonstrated that carbon-carbon (C-C) covalent bonds expand and contract flexibly in response to light and heat.
Metal wires of carbon complete toolbox for carbon-based computers
Carbon-based computers have the potential to be a lot faster and much more energy efficient than silicon-based computers, but 2D graphene and carbon nanotubes have proved challenging to turn into the elements needed to construct transistor circuits.
Cascades with carbon dioxide
Carbon dioxide (CO(2)) is not just an undesirable greenhouse gas, it is also an interesting source of raw materials that are valuable and can be recycled sustainably.
Two-dimensional carbon networks
Lithium-ion batteries usually contain graphitic carbons as anode materials. Scientists have investigated the carbonic nanoweb graphdiyne as a novel two-dimensional carbon network for its suitability in battery applications.
Can wood construction transform cities from carbon source to carbon vault?
A new study by researchers and architects at Yale and the Potsdam Institute for Climate Impact Research predicts that a transition to timber-based wood products in the construction of new housing, buildings, and infrastructure would not only offset enormous amounts of carbon emissions related to concrete and steel production -- it could turn the world's cities into a vast carbon sink.
Investigation of oceanic 'black carbon' uncovers mystery in global carbon cycle
An unexpected finding published today in Nature Communications challenges a long-held assumption about the origin of oceanic black coal, and introduces a tantalizing new mystery: If oceanic black carbon is significantly different from the black carbon found in rivers, where did it come from?
First fully rechargeable carbon dioxide battery with carbon neutrality
Researchers at the University of Illinois at Chicago are the first to show that lithium-carbon dioxide batteries can be designed to operate in a fully rechargeable manner, and they have successfully tested a lithium-carbon dioxide battery prototype running up to 500 consecutive cycles of charge/recharge processes.
How and when was carbon distributed in the Earth?
A magma ocean existing during the core formation is thought to have been highly depleted in carbon due to its high-siderophile (iron loving) behavior.
New route to carbon-neutral fuels from carbon dioxide discovered by Stanford-DTU team
A new way to convert carbon dioxide into the building block for sustainable liquid fuels was very efficient in tests and did not have the reaction that destroys the conventional device.
More Carbon News and Carbon 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

Sound And Silence
Sound surrounds us, from cacophony even to silence. But depending on how we hear, the world can be a different auditory experience for each of us. This hour, TED speakers explore the science of sound. Guests on the show include NPR All Things Considered host Mary Louise Kelly, neuroscientist Jim Hudspeth, writer Rebecca Knill, and sound designer Dallas Taylor.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

Kittens Kick The Giggly Blue Robot All Summer
With the recent passing of Ruth Bader Ginsburg, there's been a lot of debate about how much power the Supreme Court should really have. We think of the Supreme Court justices as all-powerful beings, issuing momentous rulings from on high. But they haven't always been so, you know, supreme. On this episode, we go all the way back to the case that, in a lot of ways, started it all.  Support Radiolab by becoming a member today at Radiolab.org/donate.