LEDs (Light Emitting Diodes) are semiconductor devices that emit
incoherent narrow-spectrum light when electrically biased forward.
LEDs consist of a chip made up of two semi-conducting materials, which
are separated into two areas, the n-doped side (anode) and p-doped side
(cathode). In this transfer area (p-n-junction), light arises in an interface
recombination process, where by the electron-rich (/-deficient) particles
are balanced when direct current is connected.
The dominant wavelength and therewith the color of the light depends on
the material of the semiconductor device. LEDs using AlInGaP compound
semiconductor alloys can emit in the yellow-red spectrum, while LEDs
using AlInGaN compound semiconductor alloys can emit in the
UV-blue-green spectrum. A combination of red, green, and blue LEDs, or
a blue or UV LED with phosphors can be used to create white light.
Diversifying the semiconductor materials changes the wavelengths
emitted thereof.
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Because LEDs are semiconductor devices, their performances are subject to inherent variability commonly found in semiconductor industry. To improve consistency in performance across the same product, LED manufacturers "sort" LEDs into bins according to different preset parameters, such as forward driving voltage, illumination, etc. Whereas binning is a sorting function, it is not a correction process. Inherent variability in the manufacturing process results always in different binning distributions according to different production lots. Traxon uses automatically binned LEDs on its products, thereby minimizing output variations within the model range.
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