Graphene is extremely thin. The one-atom thick carbon based material could revolutionize the way electronic devices are manufactured and used-promises to make Internet go faster, provide cheaper solar cells, new sensors, and a variety of other technological advancements: improved smart phones, and more efficient bioelectric sensory devices.
Graphene is extremely conductive and is completely transparent while being inexpensive and non-toxic.
Discovered just over a decade ago, this remarkable material is now considered as the thinnest, lightest and strongest material in the world. It is completely flexible and can conduct electricity as well as copper.
Now, researchers at the National Institute of Standards and Technology (NIST) in Boulder, Colorado, formed an encouraging new technique for a graphene substrate: a thin film of copper with large crystalline grains. It’s an optimal growth platform for the material, and by using such a right recipe, the researchers may be one-step closer to realizing graphene’s promise.
Their findings appear in the journal AIP Advances.
The significant improvement is the grain size of the copper substrate. The large grains are several centimeters in size-massive by microelectronics standards -but their relative mass allows them to survive the high temperatures required for graphene development, according to NIST researcher Mark Keller.
The inability of most copper films to survive this state of graphene development “has been one problem preventing wafer-scale production of graphene devices,” Keller noted.
Thin films are an essential component of many electronic, optical, and medical technologies, but the grains in these films are usually tinier than one micrometer. To fabricate the new copper surface, whose grains are about 10,000 times larger, the researchers devised a two-step process.
First, they placed copper onto a sapphire wafer held slightly above room temperature. Second, they added the transformative step of annealing the film at a much higher temperature, close to the melting point of copper. To demonstrate the feasibility of their massive-grained film, the researchers successfully developed graphene grains 0.2 millimeters in diameter on the new copper surface.
Now, graphene is not just theoretically remarkable, but practically considerable and applicable.