It is known for its durability, flexibility and light weight. Now graphene can add a new dimension to its bow. Scientists used it to develop the first functional semiconductor that could revolutionize electronics and computer science.
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[EN VIDÉO] This graphene bulb is the thinnest in the world! The filament of the first light bulb was already over 100 years ago…
Silicon is the king of electronics. We find them in all our devices. But gradually he reaches his limits. Relying on this alone, it is difficult to imagine ever faster computers and even smaller electronic devices. And this is where physicists have long been hoping to bring what they now call a “miracle material” into play: graphene.
Remember that graphene is a two-dimensional material. Note that it consists of only a single layer of strongly bonded carbon atoms, which gives it a number of interesting properties. For example, it is extremely durable and very light. It is also a much better conductor of electricity than copper. Problem: Graphene has no bandgap, a crucial property that allows semiconductors to turn our transistors on and off.
A graphene-based semiconductor for new electronics
And it ultimately took around twenty years until researchers at the Georgia Institute of Technology (USA) managed to produce a graphene-based semiconductor. In addition, it is fully compatible with conventional microelectronics processing methods. An essential prerequisite for the potential alternative to silicon, which they describe in detail in the journal Nature.
“Graphene has properties that we wanted to bring into electronics. It is robust, significantly more miniaturizable than silicon and can withstand very high currents without heating up or breaking down. Graphene allows us to access properties of electrons that are simply not accessible with silicon. We don’t know exactly where this will take us, but we know we have opened the door to a different way of manufacturing electronics,” Walter de Heer, a physicist at Georgia Tech, said in a statement.
From computer science to quantum computers
To get there, the physicists grew their graphene on silicon carbide wafers in special ovens. In this way they produced epitaxial graphene or epigraphene. A single layer of graphene growing on a crystalline surface of silicon carbide. The team discovered that when manufactured correctly, this epitaxial graphene chemically bonds to silicon carbide—understand that graphene donates electrons to the system—and exhibits semiconducting properties.
The results obtained by Georgia Tech physicists are much better than those of other teams developing their own two-dimensional semiconductors. In their graphene-based semiconductor, electrons encounter very low resistance. Researchers speak of a mobility ten times greater than that of silicon. Enough to consider significantly higher computing speeds. Without generating unwanted heat.
The researchers also show that the electric charges they observed can travel long distances without scattering, similar to photons in an optical fiber. In this case, tens of thousands of nanometers. In the new device, the electrons appear to exhibit quantum mechanical wave properties that are accessible in the devices, especially at very low temperatures. In this way, they could help overcome the many challenges associated with the development of quantum computers.
Graphene-based semiconductors within a few years
“For me it’s like a Wright Brothers moment,” concludes Walter de Heer. They built an airplane that could fly almost 100 meters in the air. Skeptics wondered why the world needed to fly when there were already fast trains and ships. But they persisted…”
The quantum computer saved by Majorana fermions?
Especially since, upon closer inspection, the researchers found that the currents were apparently not transported by electrons, but by a very unusual quasi-particle that had neither charge nor energy and moved without resistance. And they wonder if they just got their hands on the elusive Majorana fermion, a quasiparticle that happens to be its own antiparticle and that was predicted almost 100 years ago. So we could well be facing a real paradigm shift in the world of electronics. Even though we will probably have to wait five to ten years until the first graphene-based devices come onto the market.