The principle of LEDs was born as early as 1907. We have also written a longer article on the subject What is an LED? We have written a longer article about LED in our blog.
Here is the first paragraph of the article.
How does LED light work?
LED works like a PN diode
.P=Positive (+) and N=Negative (-). It works on the same principle, that is, it carries current in one direction only and no current can flow in the other direction. Why is this needed?
If electrons move in one direction, they form a current, which becomes the source of light in the reaction.
To make the LED work, a current is applied to it
.So a voltage is applied to the P-pin. When the holes on the P side meet the electrons on the N side at the junction of the diode, energy is released and these photons produce light.
