See-Through Transistors

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For the new transistors, "the performance in terms of the mobility, flexibility, and transparency is very impressive," says John Wager, an electrical-engineering and computer-science professor working in the area of transparent electronics at Oregon State University. Now the biggest remaining question, he says, is, "Can all of this be translated into real-world manufacturability?"

Right now, there is no method to control where nanowires get deposited on a surface or how they line up. "In experimental demonstrations, you throw down a couple thousand nanotubes and hope one aligns in the direction you want," Wager says. But randomly depositing nanowires on a surface will not work if one is to manufacture transistors for large displays.

Indeed, says Janes, "you have to have some way of putting the desired number of nanowires in the location you want." At this point, all three technologies to make transparent transistors--nanowires, thin films, and carbon nanotubes--have a fair shot at replacing silicon transistor technology for future transparent, flexible displays, Janes says.

According to John Rogers, a professor of materials science and engineering at the University of Illinois at Urbana Champaign, the ultimate commercial success of one of the three technologies will depend on how they measure up on many different factors: transparency, electrical performance, flexibility, and the ease and cost of manufacturing them. "It will be a good horse race to see which approach wins," Rogers says.