Organic Electronics: A Cleaner Substitute for Silicon. (Environews Innovations)

Frazer, Lance, Environmental Health Perspectives

Until recently, plastics--ubiquitous in most areas of modern life--had yet to make inroads into the electronics industry; their molecular configuration made them nonconducive to electrical flow, limiting their uses to shells for computers and insulation for wires. But the last few years have brought discoveries that plastic polymers can be manipulated so they may be fashioned into transistors, conductors, and other electrical components. Such uses for these carbon/hydrogen/oxygen-based polymers are the subject of the field of organic electronics.

"This is a rapidly developing industry," says Michael Schen, group leader of the Electronics and Photonics Group of the National Institute of Standards and Technology Advanced Technology Program. "We are hearing about a wide variety of potential applications, [including] transistors, electronic circuits, high-density energy storage devices, advanced emissive displays, and advanced photovoltaics." And the benefits of plastics are substantial--in many cases, researchers are finding they offer a safer, cheaper, lighter alternative to silicon.

Safer, Cheaper, Lighter

Schen says organic electronics involves a much smaller set of hazardous compounds and materials than more traditional technologies. Gone are the arsenic (used in semiconductor manufacture), phosphine (used in transistor manufacture), lead (used in the phosphorescent coating in a traditional cathode ray tube, or CRT), and mercury (used in backlights).

Silicon and silicon-based components require millions of gallons of water and temperatures of 300-500[degrees]C to manufacture. A wide range of solvents are used in silicon and in semiconductor manufacture, including highly toxic xylene and toluene. The semiconductor industry uses hundreds of thousands of gallons of such solvents annually.

In contrast, says Stewart Hough, vice president of business development for Cambridge Display Technology, his company can create components at atmospheric pressure, and at temperatures of no more than 150[degrees]C. And, although the company does use solvents with its organic technology, "we can make ten thousand displays with one liter of standard organic solvent," he says. Furthermore, says Bernard Kippelen, an associate professor of optical sciences at the University of Arizona Optical Sciences Center, it may be possible to design organics that are soluble in less harmful solvents.

Polymers also are lighter and can cost much less to …

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Publication information: Article title: Organic Electronics: A Cleaner Substitute for Silicon. (Environews Innovations). Contributors: Frazer, Lance - Author. Journal title: Environmental Health Perspectives. Volume: 111. Issue: 5 Publication date: May 2003. Page number: A288+. © 2006 National Institute of Environmental Health Sciences. COPYRIGHT 2003 Gale Group.

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