A technique invented at the California Institute of Technology (Caltech) to produce graphene--a material made up of an atom-thick layer of carbon--at room temperature could help pave the way for commercially feasible graphene-based solar cells and light-emitting diodes, large-panel displays and flexible electronics. The graphene's properties include a tensile strength said to be 200 times stronger than steel and an electrical mobility that is two to three orders of magnitude better than silicon.

Existing techniques require temperatures of 1,800 degrees Fahrenheit (1,000 degrees Celsius), which is too hot for incorporating graphene fabrication with current electronic manufacturing.

Caltech Staff Scientist David Boyd realized the need to have a clean surface devoid of copper oxide. When he tried to clean the copper under vacuum conditions, Boyd reconstructed a system to generate hydrogen gas to remove the copper oxide at much lower temperatures than usual. The technique worked, but it simultaneously produced graphene. Boyd later discovered that this occurred because of two leaky valves that allowed trace amounts of methane into the experiment chamber.

The new technique not only reduces manufacturing costs, but also results in a better product because fewer defects are generated. "Typically, it takes about 10 hours and 9-10 different steps to make a batch of high-mobility graphene using high-temperature growth methods," says Caltech Physics Professor Nai-Chang Yeh. "Our process involves one step, and it takes five minutes."

The study is published in the journal Nature Communications.

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