How Do LED Lights Do What They Do?

Light emitting diodes (LEDs) are a highly efficient light source. They have penetrated a wide range of markets from building and construction, transportation, medical devices, traffic lights and many other industrial applications, but why are they more efficient and why do they fail?

What is an LED?

LEDs are a two-lead semiconductor with a p–n junction diode that emits light when activated. Unlike incandescent bulbs and other traditional light sources, they don't have a filament and instead release photons from the p-n junction as electrons flow through the semiconductor material.

The p-n junction is constructed from a semiconductor such as gallium nitride (GaN), gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP) or gallium phosphide (GaP). Each side of the junction is doped. A p-type semiconductor is made by doping the semiconductor with acceptor impurities while an n-type is made by doping with donor impurities. Read more...

Reference:  Electronics 360
                    Shawn Martin