How does LED glow ?
The LEDs do not have any fusible filaments or elements. They also do not contain any gases such as Mercury or Sodium. Incandescent lamps produce light by heating the filament of Tungsten to very high temperatures (say >2000 Degree C) Mercury or Sodium vapour lamps have gases inside. When electricity is passed through the gas, their electrons change their energy state, and produces light. The gases have to be heated to make them have free electrons (some times even to ensure that all the mercury/sodium are in gaseous state) When electricity passes through the LED, the electrons passing through the DIODE under goes an energy change and produces the light. Since it is a “Solid State” light production without any gas or heating LEDs last for a very long time.
