How LED Works?
LED is the abbreviation of light-emitting diode. LEDs are solid-state lighting components comprised of p-type and n-type semiconductor materials. When a forward voltage is applied to the component, electrons and holes at the vicinity of the p-n junction annihilate each other, dissipating the energy in the form of photons. Depending on the band gap energy associated by the semiconductor materials used to build the LEDs, the wavelength, and thus the color, of the emitted light varies. LED development began with infrared and red devices made with gallium arsenide (GaAs) alloys. With advances in material sciences, new material systems such as gallium phosphide (GaP), gallium nitride (GaN) and indium gallium nitride (InGaN), with various band gap energies are investigated and brought into practical use, enabling the availability of LEDs with shorter wavelengths like yellow, green, blue and purple.