How an LED Produces Light

Most recent answer: 03/16/2013

Q:
how light is produced in LED?
- karthi (age 18)
thanjavur,tamilnadu,india
A:
Part of the LED is doped with atoms that release free electrons, leaving fixed positive charges. The other part is doped with atoms that trap electrons, leaving freely moving positive "holes" in the electron sea. When a current is applied in the right direction, it drives these electrons and holes together toward the intermediate region. There they can recombine, releasing energy. You can think of the process as an electron falling down into a hole. In the right materials, that energy largely comes out as blips of light, photons.

Mike W.

(published on 03/16/2013)