How Do LED Lights Work?
It’s really simple actually, and very cheap to produce, which is why there was so much excitement when LED lights were first invented!
The Technical Details: LEDs are composed of two types of semiconducting material (a p-type and an n-type). Both the p-type and n-type materials, also called astringent materials, have been doped (dipped into a substance called a “doping agent”) so as to slightly alter their electrical properties from their pure, unaltered, or “intrinsic” form (i-type).
The p-type and n-type materials are created by introducing the original material to atoms of another element. These new atoms replace some of the previously existing atoms and in so doing, alter the physical and chemical structure. The p-type materials are created using elements (such as boron) that have less valence electrons than the intrinsic material (oftentimes silicon). The n-type materials are created using elements (such as phosphorus) that have more valence electrons that the intrinsic material (oftentimes silicon). The net effect is the creation of a p-n junction with interesting and useful properties for electronic applications. What those properties are exactly depends mostly on the external voltage applied to the circuit (if any) and the direction of current (i.e. which side, the p-type or the n-type, is connected to the positive terminal and which is connected to the negative terminal).