Zee Media Bureau\Philaso G Kaping
New Delhi: Graphene, the one atom thick layer of graphite, is considered the strongest and lightest material in the world and scientists dubbed it the miracle material but its application in science and technology has been purely hypothetical.
Now scientists from the National Institute of Standards and Technology (NIST) in Boulder, Colorado, may change all that as they have developed a promising new recipe for a graphene substrate, reported the Science Daily.
A substrate is a material which can support the growth of graphene and until now scientist could not find a suitable material that could withstand intense temperature. The NIST team found that a thin film of copper with massive crystalline grains could do the trick.
“The key advance is the grain size of the copper substrate. The large grains are several centimeters in size -- lunkers by microelectronics standards -- but their relative bulk enables them to survive the high temperatures needed for graphene growth,” said researcher Mark Keller.
“The inability of most copper films to survive this stage of graphene growth "has been one problem preventing wafer-scale production of graphene devices," Keller added.
According to the press release, to fabricate the new copper surface with grains some 10,000 times larger, the researchers came up with a two-step process.
First, they deposited copper onto a sapphire wafer held slightly above room temperature. Then they made the transformative step of annealing, or heat-treating, the film at a much higher temperature, near the melting point of copper. To demonstrate that their new large-grained film worked, the researchers successfully grew graphene grains 0.2 millimeters in diameter on the new copper surface.
The finding is published in the journal AIP Advances.
