For a long time, researchers have endeavored to abuse the “miracle material” graphene to create nanoscale electronics. On paper, graphene ought to be incredible for simply that: it is ultra-thin – just a single atom thick truth be told and thusly two-dimensional, it is great for directing electrical current and ought to be perfect for future forms of electronics that are quicker and more energy efficient. Likewise, graphene comprises of carbon atoms – of which we have a boundless supply.
In theory, graphene can be modified to perform a wide range of errands inside for example electronics, photonics or sensors just by drawing minor examples it, as this on a very basic level modifies its quantum properties. One “basic” undertaking, which has ended up being shockingly troublesome, is to incite a bandgap – which is significant for making transistors and optoelectronic gadgets. Nonetheless, since graphene is just an atom thick the majority of the atoms are imperative and even small irregularities in the pattern can destroy its properties.
“Graphene is a fantastic material, which I think will play a crucial role in making new nanoscale electronics. The problem is that it is extremely difficult to engineer the electrical properties,” says Peter Bøggild, a professor at DTU Physics.
The Center for Nanostructured Graphene at DTU and Aalborg University was set up in 2012 explicitly to study how the properties of graphene can be engineered, for example by making a very fine pattern of holes. This ought to inconspicuously change the quantum nature of the electrons in the material, and permit the properties of graphene to be tailored. Be that as it may, the group of scientists from DTU and Aalborg encountered equivalent to numerous different specialists around the world: it didn’t work.
“When you make patterns in a material like graphene, you do so in order to change its properties in a controlled way — to match your design. However, what we have seen throughout the years is that we can make the holes, but not without introducing so much disorder and contamination that it no longer behaves like graphene. It is a bit similar to making a water pipe, with a poor flow rate because of coarse manufacturing. On the outside, it might look fine. For electronics, that is obviously disastrous,” says Peter Bøggild.
Presently, the group of researchers have solved the issue. Two postdocs from DTU Physics, Bjarke Jessen and Lene Gammelgaard, first epitomized graphene inside another two-dimensional material – hexagonal boron nitride, a non-conductive material that is frequently utilized for ensuring graphene’s properties.
Next, they utilized a procedure called electron beam lithography to carefully pattern the protective layer of boron nitride and graphene underneath with a dense array of ultra little holes. The holes have a diameter of approx. 20 nanometers, with only 12 nanometers between them – in any case, the unpleasantness at the edge of the holes is under 1 nanometer or a billionth of a meter. This enables 1000 times more electrical current to flow than had been accounted for in such little graphene structures.
“We have shown that we can control graphene’s band structure and design how it should behave. When we control the band structure, we have access to all of graphene’s properties — and we found to our surprise that some of the most subtle quantum electronic effects survive the dense patterning — that is extremely encouraging. Our work suggests that we can sit in front of the computer and design components and devices — or dream up something entirely new — and then go to the laboratory and realise them in practice,” says Peter Bøggild. He continues:
“Many scientists had long since abandoned attempting nanolithography in graphene on this scale, and it is quite a pity since nanostructuring is a crucial tool for exploiting the most exciting features of graphene electronics and photonics. Now we have figured out how it can be done; one could say that the curse is lifted. There are other challenges, but the fact that we can tailor electronic properties of graphene is a big step towards creating new electronics with extremely small dimensions,” says Peter Bøggild.