30-04-2012, 04:32 PM
A Brief History of LED lamps
The LED technology is not particularly recent, in fact, the first LED was developed in 1962, but it is only in recent years that has met with great approval on the market thanks to its high brightness (four times higher than a traditional source), low cost, high efficiency, making it a product that will provide greater energy savings.
Technical knowledge on LED lamps
The acronym LED ( Light Emitting Diode - light-emitting diode ), denotes a diode in which exploits the jump energy of the electrons through the junction area.
The junction is the boundary between two layers of each semiconductor doped in a different manner . In practice, applying to the semiconductor a potential difference , some electrons make a jump energy through the junction having acquired energy. Obviously the condition which is created is not stable and therefore, to re-establish a sort of equilibrium, other electrons make the reverse jump, implying that a rate of energy is emitted from the electron in that, to return to its previous energy level, must precisely re-establish its energetic condition. This amount of energy is emitted as photons that given the small thickness of the semiconductor are as ubiquitous as light. It 's useless to add that to vary the type of dopant that is used, changing the characteristics and the intensity of light emitted. What is most interesting about the white light illumination is that in itself can not be obtained directly from a LED, because these light sources emit light saturated in all colors and white as we know it can be achieved by mixing the primary colors together (which is rather difficult having to mix 3 different colors emitted by 3 different LED). Another system easier to implement, is to get as white as a result of bombardment with light blue phosphor , which absorbs blue light and emits yellow light on the mix between light blue and yellow you get white light.
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