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:

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.
How much carbon the land can stomach with more carbon dioxide in the air
Researchers from 28 institutions in nine countries succeeded in quantifying carbon dioxide fertilization for the past five decades, using simulations from 12 terrestrial ecosystem models and observations from seven field carbon dioxide enrichment experiments.
'Charismatic carbon'
According to the Intergovernmental Panel on Climate Change (IPCC), addressing carbon emissions from our food sector is absolutely essential to combatting climate change.
Extreme wildfires threaten to turn boreal forests from carbon sinks to carbon sources
A research team investigated the impact of extreme fires on previously intact carbon stores by studying the soil and vegetation of the boreal forest and how they changed after a record-setting fire season in the Northwest Territories in 2014.
Can we still have fun if the UK goes carbon neutral?
Will Britain going carbon neutral mean no more fun? Experts from the University of Surrey have urged local policy makers to put in place infrastructure that will enable people to enjoy recreation and leisure while keeping their carbon footprint down.
Could there be life without carbon? (video)
One element is the backbone of all forms of life we've ever discovered on Earth: carbon.
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

Our Relationship With Water
We need water to live. But with rising seas and so many lacking clean water – water is in crisis and so are we. This hour, TED speakers explore ideas around restoring our relationship with water. Guests on the show include legal scholar Kelsey Leonard, artist LaToya Ruby Frazier, and community organizer Colette Pichon Battle.
Now Playing: Science for the People

#568 Poker Face Psychology
Anyone who's seen pop culture depictions of poker might think statistics and math is the only way to get ahead. But no, there's psychology too. Author Maria Konnikova took her Ph.D. in psychology to the poker table, and turned out to be good. So good, she went pro in poker, and learned all about her own biases on the way. We're talking about her new book "The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win".
Now Playing: Radiolab

Uncounted
First things first: our very own Latif Nasser has an exciting new show on Netflix. He talks to Jad about the hidden forces of the world that connect us all. Then, with an eye on the upcoming election, we take a look back: at two pieces from More Perfect Season 3 about Constitutional amendments that determine who gets to vote. Former Radiolab producer Julia Longoria takes us to Washington, D.C. The capital is at the heart of our democracy, but it's not a state, and it wasn't until the 23rd Amendment that its people got the right to vote for president. But that still left DC without full representation in Congress; D.C. sends a "non-voting delegate" to the House. Julia profiles that delegate, Congresswoman Eleanor Holmes Norton, and her unique approach to fighting for power in a virtually powerless role. Second, Radiolab producer Sarah Qari looks at a current fight to lower the US voting age to 16 that harkens back to the fight for the 26th Amendment in the 1960s. Eighteen-year-olds at the time argued that if they were old enough to be drafted to fight in the War, they were old enough to have a voice in our democracy. But what about today, when even younger Americans are finding themselves at the center of national political debates? Does it mean we should lower the voting age even further? This episode was reported and produced by Julia Longoria and Sarah Qari. Check out Latif Nasser's new Netflix show Connected here. Support Radiolab today at Radiolab.org/donate.