FROM FUTURE BOY... BUSINESS 2.0

Rethinking the Lightbulb
GE, the company that brought you the lightbulb, is working on its replacement.

By Erick Schonfeld
April 30, 2004

Up near Schenectady, N.Y., in the main lobby of General Electric's (GE) research center, sits one of Thomas Edison's original desks. On its surface, under glass, are copies of the original lined notebook papers with Edison's sketches for his greatest invention, the lightbulb. That creation has enjoyed a century-long reign matched only by the fluorescent tube. But down in a laboratory two floors below, GE researcher Anil Duggal is working on something that he hopes will replace them both.

In his cramped, darkened lab, Duggal holds a 6-inch-square plate of glass that glows bright-white, illuminating his face. Inside the glass is a thin layer of plastic circuits, no more than 100 nanometers thick, that convert electricity into light. These organic light-emitting diodes (OLEDs) "have the potential to displace conventional lighting," Duggal informs me. (They also may be the future of computer and cell-phone screens, as OLED displays are already making their way into products developed by IBM (IBM), Kodak (EK), and Samsung.)

But GE's interest is in lighting. Duggal has already matched the performance of the incandescent bulb. Just last March, he produced a 2-foot-square OLED panel that creates 1,200 lumens of light, with an efficiency of about 15 lumens per watt, or the equivalent of an 80-watt bulb. What he is really aiming for, though, is the fluorescent tube, which burns with an efficiency of 100 lumens per watt. He still has a long way to go, but if he succeeds, it could change the way we light our lives.

The reason is cost. Since OLEDs are made out of polymers, they can be squirted out into circuit designs using ink-jet or other printing techniques. This could one day compete with the cost of making and using incandescent and fluorescent bulbs. And unlike other digital-lighting technologies, such as conventional LEDs and liquid-crystal displays, OLEDs can be made without sinking billions of dollars into expensive semiconductor manufacturing processes.

The key to making them cheaply, though, is to get rid of the glass entirely. While Duggal is currently printing his prototypes onto glass, he's working on ways to print OLEDs onto rolls of plastic. "The idea," he says, "is to use newspaper-like processes to manufacture these things. Newspapers are so cheap, we throw them away." GE Plastics would love that. But plastic sheets of light could also open up new design possibilities. Imagine wallpaper that acts as a light source or lampshades that don't need bulbs.

The problem with Duggal's OLEDs is that they're sensitive to moisture and oxygen. These can cause shorts or degrade the OLED material, resulting in dark spots on the panel. So Duggal is working with GE Plastics to develop a coating that protects the OLEDs from oxygen and water but remains flexible and still lets light through.

Getting the OLEDs to work and bringing the manufacturing costs down could also have implications for another technology: solar energy. It turns out that the function of OLEDs can also be reversed to convert light into energy, just like a solar panel. But, as Duggal notes, "solar energy has never been cost-effective." Before I leave his lab, he shows me an OLED solar panel connected to a small fan. He flicks on a light, and the fan starts to whirl. "This is running at 6 percent or 7 percent efficiency," he says. He'd like to get it to 10 percent efficiency. Silicon-based solar panels run at about 20 percent efficiency, but they are much more expensive to make.

Both of Duggal's projects are long-term, 10-year bets. But if he works out the kinks -- and GE commercializes the technology -- we could one day have OLED solar panels on our roofs turning light into electricity, and then OLED lighting panels in our ceilings turning that electricity back into light. Edison would have liked the symmetry of that.