Question

How does a light emitting diode (LED) work? Give two advantages of LED’s over the conventional incandescent lamps.

Answer 1

When we apply sufficient voltage to LED, electron move across the junction into the p-region and get attracted to the holes there. Thus, electrons and holes recombine. During each recombination, electric potential energy is converted into electromagnetic energy and a photon of light with a characteristic frequency is emitted, this is how LED works.

Advantage of LEDs over incandescent lamps

(1) Since LEDs do not have a filament that can burn out, they last longer.

(2) They do not get hot during use.