Rensselaer Polytechnic Institute researchers have developed light emitting diodes (or LEDs) white light with better luminous efficiency without consuming more energy.
Many marketed today LEDs combine semiconductor components monochromatic radiation to the phosphor emitting photons in a complementary color (which provides a visible white light).
However, more than half of the photons emitted by the phosphor are reabsorbed by the LED, decreasing the amount of light generated. By varying the distance between the phosphor and the semiconductor as well as the geometry of the LED lens, Nadarajah Narendran and colleagues were able to release usually absorbed photons.
Prototypes of SPE diodes (Scattered Photon Extractors) set developed by scientists have achieved under low current, greater than 80 lumens per watt luminous efficacy (lm / W), against 60 lm / W for a lamp fluorescent and 14 lm / W with a conventional incandescent lamp.
The lighting industry said solid state (SSL), which covers applications
varied (signage, street lighting, etc.), has set a target of 150 lm / W by 2012. The US Department of Energy (DOE) for its view that the spread of LEDs, known for their safety, strength and effectiveness, could reduce national energy consumption by 29 2025%. This work, published on the newspaper's website Physica Status Solidi (a), were funded by the Building Technologies Lighting R & D Program of the DOE and the National Energy Technology Laboratory.
USAT 14 / 04 / 05
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