Graphene is a high-level and efficient electric conductor but scientists have not much data to control electrical currents successfully. A new study may shed some light on its properties as they have discovered a "barrier" between the material and the semiconductor.

An atom thick layer of graphite, graphene is one of many forms of carbon. It is able to conduct electricity very efficiently but the downside is the electrons flowing could not be easily managed. Effective control of these electric currents is very important for the purposes of using this material for creation of nanoscale transistors and similar applications.

University of Wisconsin-Milwaukee (UWM) researchers did an experiment involving a 2D graphene layered semiconductor and were able to discover something new about electron transmission.

In the experiment, they demonstrated how electrons flow between the graphene and semiconductor until it encounters a problem which they dubbed as the "Schottky barrier." If this barrier is sufficiently deep, the electrons are completely blocked. However, if an electric field is applied, the electric current will pass freely.

This gave the scientists an amazing insight to electric transport: an electric field on a graphene-based mechanism may be used to control the electron flow, such as switching it off and on.

Another discovery is the characteristic of graphene which influences the barrier's height: when a graphene layer is on top of a semiconductor, intrinsic waves appear.

These ripple that forms is somewhat similar to what happens to a sheet of paper when dried after getting spilt with water. The only difference, according to author Prof. Michael Weinert is that the width of the sheet is very thin and could hardly measure one nanometer, which is one billionth of a meter.

Co-author Lian Li added , "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."

Further studies on top of their work are required to cover the various factors that affect the Schottky barrier. This will allow scientists to find the best type of semiconductor to use with graphene.

"This is a cautionary tale. If you're going to use graphene for electronics, you will encounter this phenomenon that you will have to engineer around," explained Prof. Weinert.

The study was published on the Nov. 21 issue of Nature Communications.