In a proof-of-concept demonstration, large area graphene films several atomic layers thick were inexpensively produced. These films are not perfect single atomic layers of carbon, as are the much smaller graphene flakes that have been produced up to now, but the researchers are confident that they can improve the films over time. A chemistry professor not involved in this research, molecular nanotechnology pioneer James Tour, is referenced as believing these films hold great promise for organic solar cells. Excerpts from “How to Make Graphene: A simple way to deposit thin films of carbon could lead to cheaper solar cells“, by Prachi Patel-Predd at Technology Review:
Graphene—a flat single layer of carbon atoms—can transport electrons at remarkable speeds, making it a promising material for electronic devices. Until recently, researchers had been able to make only small flakes of the material, and only in small quantities. However, Rutgers University researchers have developed an easy way to make transparent graphene films that are a few centimeters wide and one to five nanometers thick.
Thin films of graphene could provide a cheap replacement for the transparent, conductive indium tin oxide electrodes used in organic solar cells. They could also replace the silicon thin-film transistors common in display screens. Graphene can transport electrons tens of times faster than silicon, so graphene-based transistors could work faster and consume less power…
In fact, Rutgers materials science and engineering professor Manish Chhowalla and his colleagues used their graphene films to make prototype transistors and organic solar calls. In a recent Nature Nanotechnology paper [abstract], they showed that they can deposit the transparent films on any substrate, including glass and flexible plastic. Chhowalla says that the method could be adapted to a larger scale to coat “meters and meters of substrates with graphene films,” using roll-to-roll processing, a technique being developed to make large flexible electronic circuits…
James Tour, a chemistry professor at Rice University, says that this is “certainly the easiest method I’ve seen for making [graphene thin films] over large areas.” He thinks that the process could easily be converted into a larger, commercial-scale manufacturing technique. “It’s very amenable for rapid production,” he says. “It’s not going to take much to get these things produced … and cover large areas.”
—Jim
