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Displaying a Winning Glow

Plastics that emit light could revolutionize everything from wristwatch displays to TV screens. Armed with patents and scientific prowess, a British startup is leading the charge.
January 1, 1999

Jeremy Burroughes loves showing off the week’s newest color. The current special is a shocking pink. Just the sort of thing a toy maker could use to appeal to young girls, he muses. But this is no ordinary fashion statement. Burroughes, director of technical development at Cambridge Display Technology (CDT), is holding a glowing piece of plastic plugged into a bank of electronic equipment.

The pink glow comes from one of the hundreds of minuscule light-emitting diodes (LEDs) that Burroughes and his colleagues are testing in a back room of CDT’s labs in the outskirts of Cambridge, England. There, surrounded by Cambridge University and crammed into a small office building that it shares with three other high-tech companies, CDT is putting plastic LEDs through their paces, testing not just new colors but also how efficiently the devices turn electricity into light and how long they last before the light fades-crucial parameters that will determine the commercial viability of these remarkable new materials, which are known in the trade as light-emitting polymers, or LEPs.

The ambition of CDT is no less than to turn these glowing plastics into products that will revolutionize computers and TV displays, as well as toys, billboards and just about any other object that you could make out of a piece of plastic that gives off light. That ambition may be feasible because LEPs have dramatic advantages over current display technologies. And despite the university-like setting of the company, CDT’s effort is no academic pipe dream.

The company is part of what is becoming known in Europe as “the Cambridge phenomenon,” a flurry of spinouts based on technology developed at Cambridge University, one of England’s most prestigious institutions. This ancient seat of learning, in the flat and inaccessible east of England, has given birth to a cluster of high-tech companies that rival those in the city’s North American namesake. And among these young darlings of British entrepreneurs, CDT, which numbers among its founders some of the early pioneers in the development of LEPs, is a rising star.

Plastic TVs

Early last year, the company grabbed headlines around the world when it unveiled a working TV screen that measured only 50 millimeters square and only 2 millimeters thick. The device is just a crude prototype but is meant to demonstrate a replacement for the bulky bottles behind most TVs. It was jointly developed with the Japanese electronics giant Seiko-Epson, and the companies billed it as the world’s first plastic television screen. It used a simple monochromatic display and showed the British cartoon characters Wallace and Gromit in a sickly shade of green. But CDT and Seiko-Epson promise soon to show off the first full-size color display using light-emitting polymers.

The glowing polymers are gunning to become a factor in the worldwide race to commercialize technologies for flat-panel displays-thin screens that, in one projected use, could be used in a TV that hangs on the wall. For all their success in making flat screens for portable computers, technologies such as liquid-crystal and plasma displays have yet to displace the clunky cathode ray tube from the desktops of the world, let alone the living rooms. Meanwhile, newer technologies, such as field-emission devices-which essentially rely on miniaturized versions of the electron guns used in cathode ray tubes-have proven expensive to make. That leaves a big opening for the light-emitting plastics. If they can be made to work.

A commercial TV with a plastic screen is still several years down the road. In the short term, CDT and its partners plan to market LEPs for the displays in mobile telephones or the simple indicators used in such products as appliances and CD players. That’s now largely the domain of liquid-crystal displays and LEDs, and it’s a roughly $2.5-billion-a-year business. As TR went to press, Philips Electronics, which licensed the rights to CDT’s technology in 1996, was scheduled to begin test-manufacturing LEPs for these uses.

The potential has made light-emitting plastics one of the hottest areas of materials research, drawing the attention of electronics and polymer makers around the world. While it’s doubtful that any one company will dominate the business, CDT has used its strong patent position and a clever business strategy to ensure its technology plays a key role. Even more remarkable, the 33-employee startup has outcompeted some of the world’s largest materials science research groups in doing so.

Light-emitting plastics are so appealing in electronic applications because they can be used to make LEDs whose active ingredient is a tiny diode made of a polymer rather than crystals of gallium arsenide or the other inorganic materials used in conventional LEDs. Polymers can be chemically tailored to produce light of any wavelength that you care to mention; in contrast, it can be difficult to adjust the colors emitted from inorganic semiconductor crystals and some hues are particularly elusive. Polymers are also far easier to manufacture and process than the inorganic semiconductors used in current LED displays.

A further attraction of LEPs is that, unlike the liquid-crystal displays used in many laptop computers, you can view them from any angle-as anyone who has used a laptop knows, you have to stare it straight in the face to see its contents properly. What’s more, LEPs avoid the streaking, or ghosting, of images that plagues flat-panel displays using liquid crystals, because the tiny plastic light emitters can switch on and off extremely rapidly. In contrast, liquid crystals often do not respond quickly enough to keep up with the image as it flashes across the screen.

But the streaking isn’t the most serious obstacle posed by the current technologies. Liquid-crystal displays must be sandwiched between two layers of glass; and, since they don’t create light themselves, there must be a light-emitting layer behind them. What has really captured the imagination of electronics producers is that LEPs can be put down as thin films on various substrates, including other plastics. That means you could coat a cheap, flexible sheet of plastic with a thin layer of LEPs. The potential products are almost endless: from a glowing Barbie doll to screens that can be rolled up and stored to permanent, rapidly changing signs that could be put up like wallpaper.

That’s the promise. The reality is that commercializing new electronic materials is a fickle and expensive process. It takes time-and manufacturing clout. It is for precisely these reasons that CDT has hedged its bets by forming alliances with several leading manufacturers. Leveraging the strength of its fundamental science and patent portfolio, CDT has wooed many of the industry’s largest corporate players, becoming a technology partner with the likes of Philips Electronics, Seiko-Epson, DuPont and the giant German plastics maker Hoechst.

Polymer PartnersCompanyTermsObjectiveDuPont
(March 1998)Two-year joint development agreement.Supply LEPs to electronic makers.Seiko-Epson
(Feb. 1998) Joint development agreement to combine LEPs with active matrix display technology.Market full-size color displays for computers and TVs.Hoechst
(May 1997)Hoechst pays up-front fee for access to CDT’s patents.Hoechst to provide LEPs to electronic customers.Philips Electronics
(Sept. 1996)Philips pays license fee and royalty on any LEP products.Philips to initally market backlights for LCDs and displays for consumer products.

Almost Fatal

cambridge display technology may have hit on a winning market strategy, but it wasn’t always so. From the beginning, few questioned its scientific credentials. Its founders, after all, are credited with the key discovery that made LEPs possible. But like numerous other startups spun off from university research labs, CDT in its early days displayed an almost textbook case of how not to succeed, wandering away from its strengths and biting off more than it could ever chew. The company formed in 1992, adopting an almost fatal business strategy-aiming to become both a manufacturer and marketer of materials and displays.

Today, after an about-face, the company has returned to a specialized niche that seems to suit it better: technology development. It will leave the production of LEPs to its materials manufacturing partners, while its electronics partners incorporate the materials into devices.

A Bright Idea

It was several years before CDT started to go in a direction that appealed to Burroughes. That was in March 1996, when Danny Chapchal came on board. Chapchal, in his 50s and trained as an accountant, had a track record of, as he puts it, “turning around sick companies in the software business.” But, he recounts, “within about three days of arriving, I thought that I must be mad. These are people with a great idea who are hell-bent on suicide and certainly don’t want managing.” It was the company’s completely unworkable business plan that upset him, especially when he was asked to put his name to it. This called for CDT first to raise $6.5 million, followed by a further $11.5 million, with the idea of manufacturing displays and flat screens. “That was a recipe for suicide,” says Chapchal.

His answer was to turn CDT into a licensing company. It would develop its own science and technology, and enter into partnerships with large companies that had the money needed to create a new industrial infrastructure. In a business model that has become common in the biotech sector, CDT would share intellectual property rights in a number of joint development efforts.

Chapchal’s strategy quickly paid off (see “Polymer Partners,” p. 71). The first breakthrough was a licensing deal with Philips. “We had only a few months’ money left. We went to Philips for two reasons,” explains Chapchal. “They had lodged an opposition to the patent, so we knew that they were interested. And we knew that they had a team working on it.” The agreement with Philips, in September 1996, did three things for CDT, says Chapchal. It gave the company “a little bit of money that we desperately needed. When I arrived we had six months of money.” The Philips license also ended the electronics giant’s challenge to CDT’s patent. Perhaps most important, “we got publicity like you would not believe,” says Chapchal. “Within days, we had people banging on our doors saying Can we invest?’”

A second patent dispute was settled when the company signed a licensing deal with Uniax, another LEP startup based on technology developed at the University of California, Santa Barbara. With no outstanding challenges to its original patent, CDT had an asset that could be worth millions. “One of the things we have turned out to be good at,” says Friend, “is patent writing.” The core patent covers a series of claims and is, he says, “a bit like having a patent on silicon.”

Sink or Swim

in a move to strengthen its science, CDT renewed Friend’s relationship with the company. In April 1997, Friend became an executive board member and R&D director. As Chapchal describes it: “I said to him, you are claiming all the credit for inventing this thing, so now you are going to nail your flag to the mast and sink or swim by it.”

Chapchal also coaxed in a new round of investors. A group of entrepreneurs headed by Lord Young of Graffham, formerly chairman of the British telecommunications company Cable & Wireless and secretary of state for Trade and Industry in the British government, agreed to invest up to $7.5 million over four years. This was, says Chapchal, “one of the best deals I have ever done.” He is particularly pleased about the long-term nature of the investment. “I was acutely aware that no matter how good I am at managing, I have got a bunch of techies’ who want to spend money. If I had that amount of money in one year it would all go.”

Having refocused on technology development, CDT has made rapid progress. The company has now covered the spectrum with its LEPs. As well as the red, green and blue emitters that are essential for full-color images, CDT has created a palette of other colors. “There are a lot of monochrome applications that people want,” says Burroughes. For example, toy makers and companies wishing to display their corporate image in lights might be candidates for proprietary colors.

It isn’t just the technology that is racing ahead. The science proceeds in leaps and bounds, producing results that sometimes seem too good to be true. “I never thought we would get this good,” enthuses Friend. Indeed, the latest materials appear to be more efficient in emitting light than theory allows. This provides plenty of science to delight the academic scientists back at Cavendish Laboratory. Says Friend: “I never thought I would have such fun with it.”

If CDT is successful, those playing with glowing plastic toys and bendable display screens might eventually be mouthing the same sentiments.

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