Due to the technological advances of semiconductors, memory, and other electronic devices, the technology needed to continue the ever-evolving speed improvements is changing. Researchers have been looking at a new method for creating memory that is much faster from a substance found in the common pencil.

Graphene has great promise as a core technology in future generations of semiconductors. Researchers around the country and the globe are investing significant amounts of time and money into solving the problems facing the use of graphene in industry. One of the major hurdles under intense research is how to control the properties of graphene, which can be metallic or semiconducting.

Graphene is a hexagonal lattice of carbon atoms and scientists have predicted that the orientation of the atoms along the edges of the lattice would affect the materials electronic properties, but that prediction had not been proven.

According to a pair of researchers from the University of Illinois, they have now found the proof needed. Researcher Joseph Lyding, a professor of electrical and computer engineering said, "Our experimental results show, without a doubt, that the crystallographic orientation of the graphene edges significantly influences the electronic properties. To utilize nanometer-size pieces of graphene in future nanoelectronics, atomically precise control of the geometry of these structures will be required."

Lyding works with a graduate Kyle Ritter, and the pair’s findings were published in the journal Nature Materials on February 15. In the experiments, the researchers developed a method for cutting and depositing nanometer-sized bits of graphene on an atomically clean semiconductor surfaces like silicon.

The researchers then use a scanning tunneling microscope to view the electronic structure of the graphene on an atomic scale. Lyding said in a statement, "From this emerged a clear picture that edges with so-called zigzag orientation exhibited a strong edge state, whereas edges with armchair orientation did not."

He continued saying, "We found that pieces of graphene smaller than about 10 nanometers with predominately zigzag edges exhibited metallic behavior rather than the semiconducting behavior expected from size alone. This has major implications in that semiconducting behavior is mandatory for transistor fabrication."

One big benefit of graphene compared to carbon nanotubes is that graphene is a flat sheet and is compatible with conventional fabrication methods currently in use today by chipmakers around the world.

Controlling the properties of graphene is a necessity though. Lyding says, "Even a tiny section of zigzag orientation on a 5-nanometer piece of graphene will change the material from a semiconductor into a metal. And a transistor based on that, will not work. Period."

Researchers from Rice University made a breakthrough in graphene research in January that found the substrate that graphene was deposited on could control the properties of graphene. By depositing graphene on certain substrates, the researchers were able to produce either metallic or semiconducting graphene products.

The process of using graphene to build new types of memory was first covered on DailyTech in December 2008. Graphene memory promises to be much faster and require significantly less power than memory in use today in computers and other electronic devices.