Solid-state lighting is a revolutionary technology that uses semiconducting materials to create light while generating almost no heat. This is extremely energy efficient, but until recently has been impractical due to the small amount of light emitted. New developments in light-emitting diodes (LEDs) have reversed this trend, and strong interest has been shown by the US government and many research bodies.
A good introduction to the technology can be found at the Lighting Research Center (1
). It has a few presentations that demonstrate the implications of solid-state lighting, as well as highlights of various research projects. The Compound Semiconductors Web site (2
) is a good news source to learn about current breakthroughs. Abstracts of tutorials and industry outlooks are provided, which describe pure white light LEDs and other emerging technologies. Lawrence Berkeley National Laboratory has a significant research effort in solid state lighting. This presentation (3
), given in August 2002, describes the lab's motivation for advancing the technology. In a speech given by US Secretary of Energy Spencer Abraham (4
), he emphasizes the importance of solid-state lighting to reduce electricity usage. He describes the relationship between LEDs and conventional fluorescent lighting as similar to that between transistors and vacuum tubes. The Office of Building Technology offers this roadmap of lighting technology (5
). The report anticipates advances in the industry over the next twenty years, with specific attention to solid state lighting. Another report is from the IEEE Journal on Selected Topics in Quantum Electronics (6
). The authors discuss current trends in high-power LED development and results of the first solid-state lamp that is as intense as Thomas Edison's twenty watt bulb. A recent accomplishment at Sandia National Laboratories is outlined in this article from Lighting.com (7
). The "tungsten photonic lattice" is capable of converting heat to visible light and could improve electrical efficiency by over 50 percent. Another efficiency-related news story comes from researchers from a semiconductor company and North Carolina State University (8
). Their product reduces the voltage of a high-brightness LED to less than three volts, which was a long standing scientific hurdle.