Researchers in the field of microprocessors are always looking to the future to see what new materials are available as our chips get ever smaller, faster, and closer to the limits of current component manufacturing. While graphene is seen as a material of the future, it has recently been revealed that it may not be a suitable replacement for silicon in CPUs. This is due to graphene having a very small energy state gap, meaning when it is used as a transistor it cannot be turned off.
There could be ways around such a limitation that haven’t been formulated yet, but we may not need graphene for processor manufacture after all. EPFL’s Laboratory of Nanoscale Electronics and Structures (LANES) has discovered that molybdenite (MoS2) may be the perfect replacement for silicon.
Your first question, as was mine, is probably what on earth is molybdenite? Well, it’s actually an abundant material that has so far been overlooked for use in electronics. It is commonly used as an additive in lubricants and as an element of steel alloy, but now it has been found to be suitable for use as a semiconductors.
Not only is MoS2 suitable, it looks to be a better alternative than silicon for manufacturing transistors. Using the material the researchers at LANES were able to produce transistors that were both smaller and more energy efficient than what is achievable with silicon. And unlike graphene, the energy state gap is large.
MoS2’s advantages come from the fact it is a 2D material where as silicon is 3D. It’s possible to make a sheet of molydbenite much thinner than silicon while at the same time using 100,000 times less energy when in a standby state.
EPFL Professor Andras Kis explains:
In a 0.65-nanometer-thick sheet of MoS2, the electrons can move around as easily as in a 2-nanometer-thick sheet of silicon. But it’s not currently possible to fabricate a sheet of silicon as thin as a monolayer sheet of MoS2.
MoS2 is also usable in the production of LEDs and solar cells meaning this overlooked abundant material may have a bright future in the field of electronics and ultimately the gadgets we buy.
As for how abundant it is, molybdenite is the 54th most abundant element in the Earth’s crust and 25th most abundant element in the oceans. The largest producers are the U.S., China, Chile, Peru, and Canada with the largest mines being in Colorado and British Columbia. It is also produced as a byproduct of copper mining.