Graphene was discovered by Konstantin Novoselov and Andre Geim. Strong, chemically inert, transparent and thermally and electronically conductive, the material had so much potential for use in a variety of applications. The problem is, graphene is difficult and expensive to produce. All that could change, however, as a researcher discovers a means of making production faster for the material, bringing costs down by a thousand fold.
Shou-En Zhu is a PhD candidate from the Delft University of Technology in the Netherlands. In his thesis, which he will be defending in March, Zhu detailed a process of producing graphene that will not only hasten the process but will also be dramatically cheaper than current costs. Researchers have studied graphene well enough to sing praises to the material. Unfortunately, translating all that potential to an actual material is more difficult than it sounds.
When Novoselov and Geim produced graphene, they used scotch tape and pencil markings, repeatedly sticking tape against a pencil mark to thin out the graphite layer until it was just a single carbon sheet. There are several means of making graphene but Novoselov and Geim's way, known as the exfoliation method, is the best way to produce the material with the highest level of electron mobility and the lowest number of defects. Unfortunately, making graphene perfectly through this method costs over $1,000 for a flake about the size of a hair.
Zhu's method calls for a low-pressure mix of argon, methane and hydrogen over a sheet of copper heated to 1,832 degrees Fahrenheit. With the copper acting as catalyst, hydrogen is stripped from methane, leaving a layer of pure carbon sticking to the sheet.
This deposition process will typically need 10 hours to accomplish but Zhu has found a way to reduce that to one hour. This is possible by splitting the quartz tube in the oven. After deposition, the furnace is slid away to facilitate cooling.
But is graphene made through Zhu's way good enough? A demonstration took place showing graphene the size of a millimeter was indeed a single crystal by moving electrons freely around it. Free-moving electrons were pushed into circular trajectories without scattering, proving the flawlessness of the synthetic graphene.
"I want to make graphene real and bring it into daily life. Bring it into products anyone can touch," Zhu said of his future research goals.
Though just as thick as one atom, graphene is 200 times stronger than steel, as flexible as rubber and more conductive compared to copper.
