Graphene may have the potential to be an excellent conductor in quantum computing and "next-generation" electronics, but researchers still have a lot to learn about the material.
Graphene is "a one-atom-thick layer of carbon," it is so good at conducting electricity that the electrons get out of hand and are difficult to control, a University of Wisconsin-Milwaukee news release reported.
Researchers will need to learn how to control these electrons if they hope to use them in nanoscale transistors and other devices, this new study may bring them closer to accomplishing their goal.
"The group has identified new characteristics of electron transport in a two-dimensional sheet of graphene layered on top of a semiconductor," the news release reported.
The team observed that when electrons are rerouted at the graphene's interface and semiconducting substrate they go through a phenomenon known as the "Schottky barrier."
If the barrier is "deep enough" the electrons cannot pass through without a boost from an electric field; which has the ability to switch the electron's function on and off.
The team also found that when graphene is placed on top of a semiconductor it forms "ripples." The researchers compared the waves to the "waviness of a sheet of paper that has been wetted and then dried," if the sheet of paper was remarkably thin.
"Our study says that ripples affect the barrier height and even if there's a small variation in it, the results will be a large change in the electron transport," study co-leader leader Lian Li, said. According to Li, the barrier must be the whole way across in order to hold the electrons in their "on or off" state.
"This is a cautionary tale," study co-leader Michael Weinert, UWM professors of physics, said. "If you're going to use graphene for electronics, you will encounter this phenomenon that you will have to engineer around."
The researchers hope to determine which materials would be best suited for creating a graphene transistor.
