Computing

Nanotech on Display

South Korea’s Samsung leads the race to perfect flat-panel TVs built with carbon nanotubes. Will they be nanotech’s first commercial hit?

In the Samsung Advanced Institute of Technology, south of Seoul, South Korea, what looks from a distance like an ordinary 38-inch television plays an endless loop of commercials for James Bond movies. Like the displays increasingly common in American homes, it is a big, flat rectangle of color and motion in a high-tech plastic frame. But unlike the images on an ordinary TV, the ones on this lab model are generated by a layer of carbon nanotubes shooting electrons at a phosphor screen like so many tiny cannonballs. Around the world, television screens are emblems of stodgy domesticity. But this one is in the vanguard of tomorrow’s nanotechnological revolution: it could be the first commercial product that brings nanoscale electronics into the middle-class home.

Researchers around the world are racing to perfect this novel type of display, which should be brighter, sharper, and less power-hungry than current flat-panel TVs. For the moment, though, the Samsung institute appears to have the lead. “They are the ones to beat,” says Yahachi Saito, lead researcher of a rival group at Nagoya University in Japan. “They have moved very quickly.”

Samsung, and South Korean technology firms in general, are rarely thought of as the leading developers of hot new technologies. This is a stereotype, however, that the company is determined to change. “We are still identified, correctly, with low-cost manufacturing,” says Young Joon Gil, chief technology officer at the Samsung institute. But as competitors emerge from China and other east-Asian countries, he says, Samsung “must gradually move to high-profit, high-risk innovation to survive.”

Nanotechnology is the most important of the risky disciplines the company hopes to mine for new products, and the nanotube TV screens are its first fruits. Known as “field emission displays,” they should be in stores, Young says, by the end of 2006, comfortably ahead of the competition.

Meeting that prediction will not be easy. Simply taking field emission displays from the laboratory to the retail floor will require solving a host of tough technical problems. Moreover, current flat-panel displays, based on liquid-crystal and plasma technology, are constantly becoming better and cheaper, meaning nanotech researchers will have to work harder just to keep up. Even success would create its own set of problems, since Samsung – one of the world’s leading manufacturers of liquid-crystal and plasma displays, as well as ordinary cathode-ray-tube TVs – will be competing against itself.

Nanotech displays are thus both a harbinger of a technological revolution to come and an example of how a major electronics company – with lucrative, established markets to protect – is trying to manage and contain that revolution. “We believe we must master this field to grow,” Young says. “But at the same time we cannot let it wreck our company. We have to watch very carefully.”

Gunning for the Future
Field emission displays are an old idea that suddenly became more attractive in 1991, when Sumio Iijima, an electron-microscope specialist at NEC Research in Tsukuba, Japan, discovered that carbon molecules could link together into long, thin cylinders later dubbed nanotubes. (The “nano,” like the “nano” in “nanotechnology,” comes from “nanometer,” a billionth of a meter.) The tubes were like tiny sheets of carbon molecules that had been rolled up into cylinders one-ten-thousandth the width of a human hair. Scientists quickly learned that these unusual structures had a host of interesting properties, including great strength, and high electrical and thermal conductivity.

But what attracted Saito, the Nagoya researcher, to carbon nanotubes was the possibility that they could act as electron guns. Placed in a properly aligned electric field, theoretical physicists said, the little tubes should shoot out electrons like hoses emitting streams of water. Many materials emit electrons when sufficient voltage is applied; the difference, the physicists said, is that nanotubes should actually accelerate the particles along their lengths, which would allow them to emit electrons of sufficient energy to activate phosphors in very low-voltage fields. Saito, now a professor of quantum engineering, first publicly demonstrated this effect in 1998. Working with Noritake, a big Nagoya ceramics and electronics firm, he assembled a small array of nanotubes that shot electrons into a phosphor screen, creating a bright light.

Saito’s experiments had an obvious commercial target: the $61-billion-a-year world market in television sets. The cathode ray tubes inside traditional TVs have changed little since they were invented in the 1920s – in stark contrast to almost every other piece of consumer electronic equipment. They shoot electrons from the tips of wires onto phosphor screens, creating patterns of glowing dots that the human eye interprets as moving images. Cathode ray tubes are inherently bulky, because the electron gun must sit back far enough to hit the entire screen. As a result, the picture tube in a typical home-theater screen is a massive object that almost fills a room; manufacturers believe the devices would be more popular if they were more manageable.

To make thinner, lighter big-screen TVs, manufacturers have turned to plasma and liquid-crystal displays, but these have their own drawbacks, beginning with their high price (see “Screen Test,” p. 65). Plasma screens, for example, are vulnerable to “burn-in,” in which motionless images, if displayed for too long, become seared permanently into the glass. They also consume as much as 700 watts of power, enough to make some critics worry about the environmental consequences if the displays were widely adopted. In LCDs, meanwhile, pixels switch relatively slowly from one color to another, which causes fast-moving images to smear or leave ghosts as the cells fail to keep up with the action.

Field emission displays will, in theory, solve many of these problems. They aren’t vulnerable to burn-in, and they use much less power. At the same time, the pixels in a field emission display can turn on and off faster than those in a liquid-crystal display, meaning that fast-moving images don’t smear. And those images can be viewed from any angle, while liquid-crystal displays require viewers to be directly in front of the screen.

But getting carbon nanotubes to shoot electrons at a screen in an actual consumer TV will require scores of innovations in several fields – the kind of effort often best coordinated by very large companies. Indeed, about the time that Saito produced his first field emission display, he learned that he faced competition from an unlikely place: South Korea.

SCREEN TEST

Cathode ray tubes have dominated TV display technology for nearly 70 years, but today theyre locked in a four-way race for the future of home entertainment.

CATHODE RAY TUBES

LIQUID-CRYSTAL DISPLAYS

PLASMA DISPLAYS

FIELD EMISSION DISPLAYS

HOW THEY WORK

An electron beam steered by magnetic fields strikes phosphors on a glass screen

Polarized light shines through liquid-crystal “gates” that control pixels’ color and intensity

An electric pulse sets off a burst of ionized gas in each pixel, as though it were a tiny neon sign

Carbon nanotubes glued to a substrate shoot electrons at phosphors on a glass screen

STRONG POINTS

Reliable
No burn-in
Viewable from any angle
Inexpensive
Phosphors can display fast motion

Thin
Light
Reliable
No burn-in

Thin
Viewable from any angle
Pixels switch quickly
Sharp, bright images

Thin
Light
No burn-in
Viewable from any angle
Pixels switch quickly
Low power consumption

WEAK POINTS

The electron gun must sit far behind the screen, making tubes bulky and heavy

The viewer must be positioned directly in front of the screen
The pixels switch slowly, smearing fast-moving images
Expensive

High power consumption
Burn-in (motionless images displayed for too long become seared into the screen)
Expensive

Unsolved technical problems, such as maintaining a vacuum between substrate and glass
Cannot currently be manufactured affordably

Beyond the Sweatshop
South of Seoul, the urban grit of the capital gives way to lush, rolling, low hills dotted with office parks that would not be out of place in a suburb of San Francisco or Boston. In the planned community of Kiheung, one especially large complex – a set of four low, parallel structures cut through by a central corridor – houses the Samsung Advanced Institute of Technology, probably Korea’s premier private research center.

The institute is largely the vision of Samsung chair Lee Kun Hee, who established it soon after he took the company’s helm in 1987. Samsung is one of South Korea’s chaebol, the giant family-controlled holding companies that still dominate the nation’s economy. At the time of Lee’s accession it was, like most Korean electronics companies, an exemplar of what is sometimes dismissively referred to as “sweatshop electronics” – taking advantage of the nation’s low wages to undercut manufacturers in wealthier areas. It sold most of its products as commodities to better-known corporations, many of them in nearby Japan, which stuck them in boxes and slapped their own names on them.

Lee, the third son of Samsung’s founder, argued that the company’s – and Korea’s – growing success would inevitably attract competition from even lower-wage nations, especially China. Samsung, he said, would have to enter new businesses to survive; “Change everything except your wife and children!” was his rallying cry. In practice, this meant concentrating on higher-end, higher-profit products. Samsung would have to become a brand name, a symbol of quality like Sony or Honda.

To that end, Lee argued, Samsung would have to innovate, which in turn meant drastically increasing its research and development efforts. The Samsung Advanced Institute of Technology was the logical result. Slowly but constantly expanded since its creation, the laboratory now employs 950 staff, about a quarter of whom work on Samsung’s core business of semiconductors (the company is the world’s biggest manufacturer of random-access memory chips). According to company representative Lee Hyunji, institute researchers collaborate with about 120 universities and research centers in 15 countries.

Samsung now sells cutting-edge products, from superthin DVD players to video game chips. It has become the world’s third-biggest cell-phone manufacturer, with a wildly popular premium line of handsets with crisp color screens. In a list of the “most admired” electronics companies of 2003, Fortune magazine ranked Samsung fourth in the world. Samsung spent $2.9 billion on R&D in 2003; gross sales that year for the Samsung group as a whole rose almost 11 percent from 2002, to about $55 billion.

Filling the Vacuum
Field emission displays exemplify the next step Samsung seeks to take in its corporate transformation from a high-tech competitor to an industry leader. “Display technology is hugely complex to begin with,” says Kim Jong Min, vice president and director of the materials lab at the institute. “And using nanotubes adds to that enormously, both because of the unavoidable problems that always come from exploring an unfamiliar area and the fact that here there is no model to follow.” According to Kim, nanotube-based field emission displays are so complex that no single firm can develop them by itself. In consequence, researchers around the world are splitting the technology into its components and informally assigning different groups to work on each one. Samsung, for instance, does not plan to make its own nanotubes, except for research purposes. Instead, it will buy them in powder form from Carbon Nanotechnologies, a Houston-based firm with a considerable arsenal of patents in the field. A gram of carbon nanotube powder, enough to make half a dozen 40-inch displays, cost $100 last year, Kim says, but will sell for less than $10 in two years. “That is a competition we won’t enter.”

Similarly, Samsung does not intend to focus on the glue that affixes the tiny tubes to their glassy base, itself a sticky technological challenge. The company is working with DuPont to come up with an adhesive that’s thin enough to spread, strong enough to hold the ultrathin tubes by their ends, resilient enough to retain its grip despite inevitable expansion and contraction from heat, and easy enough to remove that manufacturers can clean stray adhesive from the tops of the nanotubes, so they can spray out electrons.

Nor is the company trying to gain an advantage by developing the physical components of the display itself – the spacers that hold apart the top and bottom sheets of the screen, the high-vacuum packaging, the driver circuitry, and other standard field emission components and materials. Instead, it has joined a consortium of more than half a dozen European companies and universities created specifically to tackle those problems and incorporated the group’s early results into the 38-inch display now showing off Pierce Brosnan’s Bond-blue eyes.

Delegating these aspects of field emission display design still leaves plenty for Samsung to work on, beginning with the glass itself. The nanotubes have to shoot their electrons across a vacuum; otherwise they would be absorbed or deflected by air molecules. Yet making what amounts to a very wide, sheetlike vacuum chamber is difficult, because over a large area air pressure will tend to crush together the two sides of the screen. The obvious answer is to put a support pillar in the middle of the screen. But then, Saito explains, “you see the support in the middle of the picture.”

Equally problematic, in his view, is the thermal expansion and contraction of the display. When the nanotubes are emitting electrons, the display gets hotter, and all its materials expand; when the electron beam is off, they shrink. “The problem is how to accommodate the expansion,” Saito says. His team had to find materials whose thermal expansion coefficient was the same as that of glass, so that the entire display would expand and contract in concert.

Exactly how Samsung pulled all these pieces together is “our secret,” says Kim. “That’s what we do: we’re a company that makes devices.” But key to Samsung’s decision to focus on field emission displays, he admits, is the lucky fact that they can tolerate imprecision. With current technology, aligning the nanotubes across the back of the display is an inexact process. The tubes point in a jumble of different directions, and most are too broken or bent to emit electrons successfully. Fortunately, nanotubes are small: about 10,000 cover each pixel in the display. As a result, Kim says, “We expect that only 30 to 50 percent of them will work, but we only need 30 to 50 percent to light up the pixel and deceive the human eye.”

Samsung is pleased enough with the result to permit a journalist from Technology Review to be the first non-Korean reporter to visit the Advanced Institute of Technology. Walking through the institute’s maze of small fluorescent-lighted laboratories, each with its coterie of white-coated researchers and glowing computer screens, Kim says that the display consumes about 100 watts, about a third of the power required for an average plasma screen of comparable size. “That’s just for now,” he adds. A bare two millimeters thick, the glass of the screen is thin enough to make the display slimmer than anything now on the market.

Arriving at the display, Kim introduces it with the slight anxiety of a proud parent hoping that strangers will appreciate the special qualities of his offspring. The image is as sharp as those produced by traditional high-definition picture tubes with similar display sizes, though the screen has several small blank spots. (“Prototype difficulties,” Kim explains.) Asked whether the technology is almost ready for market, the scientists in the room look at each other uncertainly. Samsung, Kim finally says, has just begun to work on the real challenge in bringing nanotechnology to the world: making the product affordable. The economic problems, he says, “are much, much harder than the technological ones.”

Lucky $7
Samsung is not alone. Two hours away in Japan, Saito’s success – and fears of being eclipsed by Korea – led the government’s New Energy and Industrial Technology Development Organization to establish a $37 million, 2.5-year national project to crash-develop field emission displays. Launched in 2003, the project has four main participants: Hitachi; Asahi Glass; a Nagoya University-Noritake collaboration directed by Saito; and a joint effort by Mitsubishi, Kyoto University, Osaka University, and Osaka Prefecture University. “The Koreans are still ahead of us,” Saito says. “But we are working hard to catch up.”

So are a dozen other companies in Japan, Europe, and the United States. It is generally believed that the leaders are Noritake, Mitsubishi, Motorola, and the French Atomic Energy Commissariat’s Laboratory of Electronics and Information Technology in Grenoble. Motorola demonstrated a small prototype in 2002; last year, the French laboratory demonstrated several, as did a small, secretive Silicon Valley startup, cDream.

Nanotechnology is frequently described as a technology with the potential to capsize the established order. In a theory often touted by business consultants, an industry’s largest incumbents are unlikely to develop such technologies, for two reasons: first, they are less profitable in their initial stages, and second, they have the potential to undermine existing products. Eventually, a small startup does develop the technology, using its sharp technological edge to overwhelm the competition and ultimately rocking the establishment.

Whether field emission displays fit this model remains to be seen. Nanotubes have obvious technological advantages on paper, but in the marketplace they are far from overwhelming. Right now, 42-inch plasma displays typically retail for $2,500 to $3,500; large liquid-crystal displays range from about $5,500 to $7,000. But the cost of both technologies is plummeting. “The manufacturing cost per diagonal inch of plasma displays will be about $9 in 2005 and 2006,” Kim says. “But because we have startup costs, we have to beat that by a considerable margin – $7 a diagonal inch, say.”

Luckily for Samsung, production methods for field emission displays are similar enough to those for plasma displays that it can use one of its current fabrication plants to build the devices, avoiding the overhead costs of an expensive new factory. Yet if plasma displays keep getting cheaper, Kim says, “we will lose our opportunity,” and field emission displays will not replace them. And even if Samsung reaches the magic $7 number, he says, to stay competitive it’ll have to shoot past it, to perhaps $5 per inch. Nanotechnology can be “a disruptive technology for displays,” Kim says. “But the conventional methods can disrupt it back.”

Indeed they can. In July, Samsung SDI, the company’s display subsidiary, announced that next year it will introduce a standard CRT for a 32-inch television screen that is only 14 inches deep, half the depth of existing picture tubes. Televisions with the new “Vixlim” tube, the company promised, will shrink from two feet in depth to 15 inches; they will also have better-quality images than either plasma or liquid-crystal displays and be up to a third cheaper. By the end of 2005, Samsung SDI predicts, the new tubes will be in every large standard television it makes. Standard picture tubes, according to company representative Lee, will enter a “new boom period.”

Asked about the new Samsung CRT, Kim emits a mock groan. “They are very good researchers,” he says. If field emission displays cost three times as much as CRTs and are only somewhat thinner, he acknowledges, nobody will buy them. Still, he believes that by covering its bets, the company as a whole will come out a winner. So will the consumer, who will enjoy steadily falling prices. In Kim’s view, field emission displays will eventually prevail, becoming the leading edge of an approaching wave of nanotechnological products. But the race will be a lot closer than subsequent business histories will make it seem.

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