LED light for
outdoor and indoor:
LED street light
LED traffic light
Like a normal diode, the
consists of a chip of semiconducting material
impregnated, or doped, with impurities to create a p-n
junction. As in other diodes, current flows easily from
the p-side, or anode, to the n-side, or cathode, but not
in the reverse direction. Charge-carriers—electrons and
holes—flow into the junction from electrodes with
different voltages. When an electron meets a hole, it
falls into a lower energy level, and releases energy in
the form of a photon.
The wavelength of the
and therefore its color, depends on the band gap energy
of the materials forming the p-n junction. In silicon or
germanium diodes, the electrons and holes recombine by a
non-radiative transition which produces no optical
emission, because these are indirect band gap materials.
The materials used for the
have a direct band gap with energies corresponding to
near-infrared, visible or near-ultraviolet light.
development began with infrared and red devices made
with gallium arsenide. Advances in materials science
have made possible the production of devices with
ever-shorter wavelengths, producing light in a variety
LED light is a
type of solid state lighting (SSL) that utilizes
light-emitting diodes (LEDs) as a source of illumination
rather than electrical filaments or gas.
LED light (also
called LED bars or Illuminators) are usually clusters of
LEDs in a suitable housing. They come in different
shapes, including the standard
light bulb shape
with a large E27 Edison screw and MR16 shape with a
bi-pin base. Other models might have a small Edison E14
fitting, GU5.3 (Bipin cap) or GU10 (bayonet socket).
This includes low voltage (typically 12 V halogen-like)
varieties and replacements for regular AC mains (120-240
Currently the latter are less widely available but this
is changing rapidly.