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Wednesday 12 December 2018
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How Do LEDs Work?

LEDs (short for Light Emitting Diodes) are found in a wide range of electronics. From traffic lights, to remote controls, to TVs, LEDs truly are a staple of the electronics world.

What Are LEDs?

LEDs are nothing more than tiny light bulbs with two metal leads that can be easily attached to a circuit.

What Makes LEDs So Special?

The main thing that makes LEDs so special is that they don’t have any filament like there is in ‘normal’ light bulbs, so there is nothing to produce heat and nothing to burn out. This makes them last infinitely longer than traditional light bulbs. The light in LEDs is created via the rapid movement of electrons in a semiconductor. The amount of electricity or power required to move the electrons is far less than what is required to illuminate traditional light bulbs. As a result, LEDs consume up to 80% less electricity. And they all come in different sizes, from light bulbs to mini LEDs fit for hobby projects. And they are often very cheap.

How Do They Work?

All LEDs contain a semiconductor diode. One side of that semiconductor diode is attached to a cathode while the other one is attached to anode. Electricity flows from anode to the cathode. So, when it passes through, the electrons flow through the semiconductor and switch to different energy levels. Because of this change in energy levels, a photon of light is produced by the electrons. These photos are then focused through a lens that provide the light that we see, without any flicker.

The reason small LEDs can produce light is because of the two semiconductor materials and their specific arrangement between its electrodes. The semiconductors in question are P-type and N-type semiconductors. P-type semiconductor contains extra holes and have extra particles with a positive charge. N-type semiconductor on the other hand, contains extra particles with a negative charge.

Although generally all diodes emit electromagnetic energy particles called photons, LEDs have specific kinds of diodes that emit energy in the form of light instead of heat. An LED is a solid-state lightning (SSL) technology. What this means is that it produces light from a solid piece of matter. The solid piece of matter in an LED is a 2-lead semiconductor.

How LEDs Produce Different Light Color?

Generally, the material (for conductivity purposes) used in LEDs is Aluminum-Gallium-Arsenide or AIGaAs. Apart from this, there are a variety of alternative kinds used. These materials are selected due to their ability to produce photons. These photons when released, appear on the visible section of the light spectrum. The type of material selected and its amount used determines the color of the light because all such materials produce photons containing different wavelengths. This affects how they appear on the light spectrum and how our eyes perceive them.

Interesting Fact: There Are No Pure White LEDs

White LEDs don’t exist, at least not anything that is purely and completely white. Any so-called white mini LED light you find on the market either has a yellow or orange coating (usually phosphor) that changes the color of the LED into white light. Either that or it consists of a variety of different colored LEDs.