Scientists have been researching for a long time to increasing the number of transistors onto a chip and have been examining the potential of graphene for a number of years now. But graphene is not the only two-dimensional material capable enough. Another promising and capable candidate was revealed by the researchers at McGill University and Université de Montréal, providing insight regarding the candidate that may allow chip designers maintain speed with Moore’s Law. The candidate is the Black Phosphorus.
Graphene provides high electrical conductivity and is a one-atom thick material. But when used as a zero bandgap semiconductor, graphene start acting like a metal, thus the transistors made from this material cannot be easily switched on and off.
Phosphorene is the one-atom thick layers that can be achieved by separating the Black Phosphorus. When used as a semiconductor, phosphorene can be easily turned on and off, unlike graphene. This in turn lowers the energy consumption by the transistors due to ease of switching and also lowers the amount of heat the transistors generate.
According to Thomas Szkopek, The Associate Professor and Senior Author of this new study, “Transistors work more efficiently when they are thin, with electrons moving in only two dimensions, nothing gets thinner than a single layer of atoms.”
There exists a slight problem though. As this material reaches the two-dimensional state, black phosphorus takes damage from light, which will cause trouble in the creation of single layer transistors.
At the National High Magnetic Field Laboratory in Florida, the highest-powered magnet laboratory in the World, the researchers found that the electron still travel only in two dimensions, even when thicker sheets of black phosphorus are used.
“What’s surprising in these results is that the electrons are able to be pulled into a sheet of charge which is two-dimensional, even though they occupy a volume that is several atomic layers in thickness,” says Szkopek.
This finding about the 2D electronic structure being independent of the 2D atomic structure could lead to implications and eventually to the manufacturing of the material on a large scare, though it might still be a little off.
“There is a great emerging interest around the world in black phosphorus,” Szkopek says. “We are still a long way from seeing atomic layer transistors in a commercial product, but we have now moved one step closer.”