How LEDs Work
LED lights are convenient, have various uses, and are much cheaper than traditional fluorescent lights. But you may be curious as to how these tiny light bulbs work.
LED stands for "light emitting diodes" and are found in all kinds of electrical appliances from digital clocks, watches, illuminating traffic lights and transmitting signals from remote controls, enough of them jumbled together provide the images we see on jumbo TV screens.
Diodes are the most fundamental kind of semiconductor devices. Generally, a semiconductor is a material with a versatile ability to act as a catalyst for an electrical current. Several semiconductors are constructed from lackluster conductors that have had impurities such as atoms of other materials added to it. The process of adding such impurities is known as "doping."
With LED lighting, aluminum-gallium-arsenide (AIGaAs) is usually the conductor material. The atoms are perfectly attached to their neighbors in pure aluminum-gallium-arsenide, leaving no free-floating electrons (particles with a negative charge) to act as a catalyst for an electric current. In impure materials an abundance of atoms shift the balance, either adding radical electrons or making holes where electrons can go.
A semiconductor that has an extra electron is known as an N-type material, named so because of the extra electrons. With N-type materials, free electrons shift from a negatively-charged area to an area with a positive charge.
A semiconductor that has extra holes is know as a P-type material because it has extra positively-charged particles. Electrons can then traverse from hole to hole, jumping from a negatively-charged area to an area with a positive charge. Because of this, the holes seem to shift from a positively-charged area to a negatively-charged area.
Diodes have a section of N-type material combined to a section of P-type material. This then conducts electricity in a single direction. The interaction between electrons and holes creates light.
A depletion zone is created when there is no voltage applied to the diode and electrons from the N-type material fill in the gaps from the P-type material along the junction in between the layers. In the depletion zone the semiconductor material goes back to is original insulating state, barring a charge from flowing.
Some of the advantages of LED lights are that they are green, meaning that that they are eco-friendly and don't require as much electricity as florescent lights to work, and they also don't burn out and last much longer.