Incandescent light bulbs have been used to illuminate homes, offices, schools and factories ever since Thomas Edison developed the technology more than 120 years ago. But, the common object that most people take for granted may soon become a collector’s item.

Researchers at Sandia National Laboratories (Albuquerque, NM) are developing solid-state lighting technology. They predict that semiconductor light-emitting diodes will eventually become the nation’s primary lighting source.

"In some ways, the revolution in lighting can be compared to the revolution in electronics that began 50 years ago and is only now reaching maturity," says James Gee, a senior scientist at the U.S. Dept. of Energy laboratory. "Just as for electronics, glass bulbs and vacuum tubes are giving way to semiconductors. And as in the microelectronics revolution, many of the possible applications for solid-state lighting will occur in ways that have not yet been envisioned."

Light-emitting diode (LED) technology is already found in toys, electronics, traffic lights, automobile signals, large outdoor displays and other applications that require durability, compactness and cool operation. In some applications, LEDs also enable significant cost savings due to their lower consumption of energy. For example, LED-based red traffic lights consume one-tenth the energy of their incandescent counterparts.

As the technology matures, Gee predicts that solid-state lighting will "rapidly outdistance conventional lighting sources in both performance and cost." He claims that LEDs could be 10 Arial more efficient than incandescent bulbs and two Arial more efficient than fluorescents.

Gee says LED technology was first demonstrated by General Electric 40 years ago. The first products were introduced in 1968 by Hewlett-Packard, but LEDs were limited to small-signal applications until 1985 when power capacity was increased. Today, LEDs can produce red, green and blue light, making it possible to generate white light for illumination.

However, LED-based light sources are not cheap. In fact, Gee claims they are several Arial more expensive than commercial incandescent light bulbs. The technology will not be practical until costs are reduced and efficiency is further increased.

The Sandia researchers are focusing on areas such as:

  • Understanding the physics of the gallium nitride-based materials that are the base materials of LEDs.
  • Improving optoelectronic devices and materials for abundant photon generation and high light extraction efficiency.
  • Improving wavelength conversion and color mixing technologies for generation of white light.
  • Improving packaging technologies for high-power LEDs.