For a few years now, you may have heard of graphene as the almost magical solution to the limitations of PC processors today. This topic has been in development for more than a decade, and yet, why are there still no processors made with graphene ? Below we will explain why there is not, nor will surely be, graphene processors at the end.
There have been many promises around graphene in processors ; Without going any further, in 2018 the Catalan Institute of Nanoscience and Nanotechnology (ICN2) made a discovery by means of which it was possible to manufacture graphene transistors – which would later be used in processors -, multiplying their power. However, time goes on and there is no more news about it. What is happening?
Graphene processors, why aren’t they possible?
Graphene is nothing more than a very thin layer (of the thickness of an atom) of carbon, which long ago was discovered to be superconducting , that is, it is capable of letting electricity pass without putting up practically any resistance, so the speed and efficiency are almost absolute.
The problem is that with current technology it is impossible to build semiconductor transistors, and this is so because as graphene is superconducting, it would not have an “off” state. A transistor is nothing more than a switch that allows or does not allow electricity to pass, representing the ones and zeros of the binary system, and at this time graphene is not capable of generating zeros, represented when it does not let current pass .
This is known as “Band Gap” (something like band gap), and we will explain it in detail below.
Band Gap, the graphene problem
The Band Gap is a small gap between a conduction band and a valence band that tells us what level of current will actually flow between the two. It is like a small doorman that maintains the electrical charge in a space until it “turns off.” Virtually all processors are made of a semi-conductive material, which means that it has a moderate band gap that makes it not conduct electricity as easily or reject all electrical charges. This has to do with the basic molecular structure, so there is quite a bit of chemistry involved in building the chip.
There are very large Band Gaps in materials such as rubber that will resist both electrical currents, which before letting them pass will jump into flames (that is why rubber is used to insulate the cables). Materials with a very low Band Gap are known as conductors, while those with practically none are called superconductors, such as graphene .
Today most processors are made of silicon, which serves as a very strong and reliable semi conductor. Remember that we need semi conductors that can be turned on and off to be able to act as “switches” and represent the ones and zeros of the binary system, and for this a superconductor does not work. This is why there are still no processors made from graphene.
Other materials to make processors
One of the problems that silicon has is its inflexibility when working on very fine surfaces. A piece of silicon must have a minimum thickness to be functional, and that is why the possibility of using graphene instead is being explored (since its thickness is that of an atom, but as we have explained in this case, being superconducting is a disadvantage). Since graphene, while promising, requires an investment of time and money too large for the profitability that would be obtained for the future, scientists began to experiment with other materials .
This is where TiS3 (Titanium Trisulfide ) appeared, a material that not only has the ability to work even with the thickness of a single molecule, but also has a Band Gap quite similar to that of silicon.
The implications of this could be far-reaching for technology products, which tend to be smaller and smaller with the aim of putting more transistors in the same space, multiplying power and efficiency. This has another added advantage: a thinner material has an easier time dissipating heat, making it even more promising for use in testers.