Polymers to Pixels
Company: Philips Electronics
Benefit: Cheap, high-quality flat-screen TVs
By Jessica Gorman
Electronics superstores like Best Buy are bustling right now, as holiday shoppers search for the perfect gift. Some of the big-ticket items are the most mesmerizing – row after row of 50-inch flat-screen TVs costing thousands of dollars. But in a few years, if ongoing research at Philips Electronics succeeds, stores will offer a new, cheaper option: a flat-screen TV that brings images to life with a layer of light-emitting diodes that use novel organic molecules.
Philips, one of the world’s largest makers of flat-screen plasma and liquid-crystal displays (LCDs), has spent more than a decade at its labs in Eindhoven, the Netherlands, working to perfect the polymer-based screens. The technology, says Nijs van der Vaart, the leader of the project at Eindhoven, “has so many advantages.” For one thing, black is “very black,” while LCD screens allow light to leak through blacked-out pixels. And unlike LCDs, the new technology allows viewing from any angle; it also eliminates the shadows that follow fast-moving objects like soccer balls. But the advantage that consumers might find most eye-catching is a price that’s potentially lower than either plasma or LCD televisions’; in theory, at least, manufacturing displays out of light-emitting plastics will be far cheaper.
Philips’s new type of display relies on a fundamental breakthrough in materials science. Normally, polymers don’t emit light, but in 1989 physicists at the University of Cambridge developed a new type of plastic that shone brightly when sandwiched between electrodes. Philips started research on the new technology soon after. For a display manufacturer like Philips, the implications were obvious: selectively addressing small areas of the polymer layer with electricity would get those areas to selectively emit light. In other words, you could make pixels.
Philips is not without competition in trying to come up with a better flat-screen display, but it hopes to gain an edge by leveraging its expertise in chemistry and materials science. Van der Vaart and his research colleagues are looking for further ways to improve the light-emitting properties of the polymers. They have also built a novel ink-jet printer that uses separate print heads to deposit the polymers as red, green, and blue pixels. Philips believes this printing system is potentially a cheap and versatile way to make the supersize television screens.
One problem that Philips’s researchers continue to wrestle with is the light-emitting lifetime of the polymers. In particular, Philips’s blue polymer fades after far less use than the roughly 20,000 hours a television needs to be able to endure. Another challenging problem is that some parts of the polymer-LED screen fade before others. And to make a 30-inch TV screen, Philips’s researchers must improve the display’s efficiency, so that smaller currents will elicit the needed light from the polymers.
But after more than a decade of work, the research is beginning to yield results. In 2002, the company introduced the technology in a display on an electric shaver. In 2004, Philips released a cell phone with a small polymer-LED display. Larger, higher-resolution displays will probably appear in cell phones around 2005, says van der Vaart, who is optimistic that a 30-inch or larger TV could reach stores by 2008.
In the meantime, holiday shoppers who want cheap flat-screen televisions based on brightly glowing polymers will have to wait. Perhaps an electric shaver would make a nice gift instead; you could even get one with a polymer display.