Graphene: It won't replace silicon, but it still has a €1bn future

So-called 'wonder material' graphene may be many things, but a replacement for silicon? Not so much, says the head of the graphene flagship that won €1bn in funding last month.
Written by Liam Tung, Contributing Writer

Graphene may be many things, but it's not a replacement to silicon, according to the director of a €1bn project tasked with finding ways to exploit it.

"We don't say replacement [for silicon]. We say complement," says Jari Kinaret, a professor in the Department of Applied Physics at Chalmers University of Technology in Gothenburg, Sweden.

Kinaret is the director of the Graphene Flagship, which was recently named the winner of the European Commission's Future & Emerging Technology competition and one of two "flagship" programmes earmarked to receive €1bn in funding over the next 10 years.

The flagship aims to find ways to exploit the potential of the one atom thick, carbon-based material for industrial uses in electronics, transport, imaging, communications and sensors.

Some of Europe's biggest tech companies are early contributors to the project, including Nokia, Philips and STMicroelectronics. Outside ICT, there's also aircraft manufacturer Airbus, energy firm Repsol, and, according to Kinaret, a long line of other companies keen to participate.

"Already, after the announcement, I've been bombarded by mail from various directions — particularly from industry — saying they want to be part of this," he says.

The European Commission will directly fund about half of the project's headline figure, while industry participants and other sources are expected to make up the rest.

Despite numerous early successes building electronics from graphene, the real pay-off from developing the material are expected to be delivered over the long term. Some experiments in recent years perhaps don't capture how far off its applications in electronics may be.

Take the graphene transistors IBM demonstrated back in 2010, for example. Graphene offers superior conductivity and speeds to copper and silicon but the flip side, said Kinaret, is that graphene transistors are difficult to turn off — a feature that researchers at Manchester University are trying to solve.

"That is a big obstacle if you want to create digital electronics because in digital electronics you really want the off-state to be off — so that no current flows and there is no dissipation when your transistor is in the off-state. It's a big challenge to turn graphene transistors fully off so digital electronics is going to take a very long time, probably considerably more than 10 years to develop," said Kinaret.

In Kinaret's view, graphene merely presents an opportunity to add capabilities to an element that does a good job with today's electronics. 

"There is absolutely no reason to replace silicon in many things. For digital electronics, silicon works very nicely, but there are some things that silicon can't do such as the possibility to integrate optics and electronics in a way that cannot be done with silicon," he said.

Another question is around how high quality does graphene need to be for industrial materials. Printable electronics using composite materials will be easier to do than high-performance and high-frequency electronics using graphene. Indeed, the first place graphene is expected to land is in sports equipment, such as tennis rackets, but exploiting the material's light, strong and flexible properties, there are also applications in aerospace, cars, or medical for t.

The biggest challenges may not be technical, however. For example, graphene's ability to deliver terahertz frequency radio could be applied to imaging, yet today's component supplies only cater to engineers specialising in x-ray optics at one extreme and ultrasound at the other.

"[Terahertz frequency imaging] is very difficult to study today because terahertz is somewhere above the frequency range where radio engineers feel comfortable and below the frequency range where optical experts feel comfortable. It's somewhere between two existing technologies and there is a shortage of components that can function in that frequency range, so it has not been fully developed yet," Kinaret said.

Kick-starting that ecosystem of suppliers will be the big challenge for the next decade and is one of the programme's main goals.

"The biggest issue is getting all the players to play together," said Kinaret. "But in this flagship programme we have the people who are interested in the materials production, people who make components and people who take the components and integrate them together. That allows us hopefully to take graphene and the related layer of materials from academic level to society where they can benefit society in the form of new products and new investment opportunities."

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