“There are a lot of interesting things you could do if you had truly transparent electronics,” Marks says. “You could almost envision a display floating in space.” The displays could also be applied to glasses or helmet visors. “You could imagine an assembly-line worker, a race-car driver, or some military application where you might want a map or something like that on your visor.”
The new transistors’ ability to challenge silicon in performance suggests that they could be used not just as pixel switches, but also as transparent processors and memory–all of which could be incorporated into a thin, flexible sheet, saving manufacturing costs and introducing a new form of electronics. Such applications are still a long way off and require improving the performance of the transistors. But prototype displays based on the new transistors could be ready in as little as 12 to 18 months, Marks says. Polyera, a startup in Evanston, IL, has been founded to help bring the novel materials to market.
The Northwestern researchers are not the first to combine organic and inorganic materials into transistors: as early as 1999, IBM researchers produced such devices (see “Flexible Transistors”). However, these were not transparent and did not perform as well as the Northwestern transistors. Others are now working toward transparent electronics using materials such as zinc oxide and carbon nanotubes, says John Rogers, professor of materials science and engineering at the University of Illinois, Urbana-Champagne. While the carbon nanotubes could theoretically lead to significantly better-performing devices, manufacturing arrays of nanotube-based devices will be much more difficult than those made with the Northwestern techniques. The new work is also distinct from some prototype flexible displays, which still rely on visible wires.
“This is some very nice work from one of the leading groups in low-temperature materials for electronics,” Rogers says. “The performance that they achieve is very impressive. This paper represents a valuable contribution to the emerging field of transparent electronics.”