Simple Spray Makes Flawless Graphene Layers

Researchers have developed a technique that allows them to create thick layers of graphene that are utterly defect free. This could open up a whole new realm of possibilities for the advancement of electronics.

Graphene is strong, transparent, and a fantastic electrical conductor, making it the ideal material for hundreds of difficult scientific endeavors. However, production of the material has always been difficult, holding back what the promising conductor can do for electronics.

"Normally, graphene is produced in small flakes, and even these small flakes have defects," University of Illinois at Chicago (UIC) researcher Alexander Yarin explained in a recent statement.

According to Yarin, when you try to deposit these flakes onto a large-scale area, the defects only increase, and graphene's highly conductive properties are lost.

However, new research conducted by UIC in collaboration with scientists from Korea University has revealed that graphite flakes can be coated in a smooth and flawless layer on any surface if they are applied using a "simple" spray method.

According to a study published in the journal Advanced Functional Materials, the researchers determined that they could deliver the graphene flakes in an evenly distributed manner if they were embedded in very small droplets of graphene suspension, which evaporate rapidly. The droplets are fired out of the spray with "supersonic" acceleration, reducing the tendency of the graphene flakes to aggregate.

Interestingly, the researchers were surprised to learn that the spray system also eliminated minor defects in the flakes.

"Imagine something like Silly Putty hitting a wall - it stretches out and spreads smoothly," said Yarin. "That's what we believe happens with these graphene flakes. They hit with enormous kinetic energy, and stretch in all directions."

According to a UIC press release, other attempts to produce flawless graphene have proved difficult and expensive, but this spray is relatively inexpensive and remarkably effective. In-fact, the technique is so effective that the research teams are moving on to attempt to test this spray in industrial applications.

The study was published in Advanced Functional Materials on May 26.