Because solid-state lighting is a new technology, it will bring with it a number of new system-level attributes. These include programmability, small volume, ruggedness and immunity to vibration, compatibility with environmental extremes (cold and heat), and an enhanced efficiency in directed illumination. Ultimately, these system-level attributes are expected to enhance considerably the competitiveness of solid-state [...]
The first known report of a light-emitting solid-state diode was made in 1907 by the British experimenter HJ Round. However, no practical use was made of the discovery for several decades.[18] Independently, Oleg Vladimirovich Losev published “Luminous carborundum [[silicon carbide]] detector and detection with crystals” in the Russian journal Telegrafiya i Telefoniya bez Provodov (Wireless [...]
Technological developments in the last two decades have allowed LEDs to be used in signal devices, like traffic lights and exit signs, and in some limited illumination applications, such as flashlights. However, cutting-edge research now shows a bright future for solid-state lighting as the next generation of light sources for general illumination, from homes to commercial applications. The Lighting Research Center is working to make that happen.
In the past 12 months, a new light source has emerged that is sufficiently bright and efficient to be used for general illumination. The light emitting diode, commonly called the LED, uses far less energy and can last many times longer than most bulbs and contains no lead or mercury.
The history of man-made light is based on heat. Wax, oil and gas burn to produce light. The filament in an incandescent bulb heats up to produce light. Gas in a fluorescent tube is zapped to illuminate. The basic method is “Heat it up, and it glows.”