LEDs have become the world-leading light source in recent years due to their highly efficient designs and wide-ranging capabilities, but what they are and how they work is not widely understood.

Below, we explain the answers to common questions about LED technology.

What is an LED?

LED stands for Light Emitting Diode. It is a component which converts an electrical current into visible light.

Diodes only light up if electricity passes across them in the right direction, they will not light up if they are installed the wrong way around.

The Positive/Negative (P/N) junction in the middle of an LED consists of an anode (the positive side) and a cathode (the negative side), both made of semi-conductive material.

How does an LED work?

LEDs rely on an effect called electroluminescence. This is the conversion/transference of electrical energy into visible light, by running an electrical current through a material, usually tiny human-engineered crystals.

Electroluminescence is very complex, because it relies on changes to very small particles and highly technical processes.

Electrons travel across the negative cathode into the positive anode, and when they undergo this change, their energy-potential also changes. These electrons are filling “electron-holes” on the other side of the junction, which allows an energy-transfer. When this is correctly balanced, the energy change emits a light particle called a photon, with the same energy as that which travelled across the P/N junction.

After over 100 years of research, scientists have learned how to capture and reflect this light efficiently, so that we can see it more easily. This has made LED technology what it is today.

How is this different from incandescent bulbs?

It’s all about the heat!

Incandescent bulbs work very differently. Rather than converting electrical energy straight into light, incandescent bulbs use heat - and a lot of it! There is so much heat energy in the filament of an incandescent bulb that the metal inside it lights up very brightly.

While the development of the light bulb was a great stepping stone in modern civilisation, this process is sadly very inefficient. Incandescent bulbs waste up to 95% of energy on heat, rather than light. As a result, many people have burned their hands changing these bulbs, while hurting their wallets in the process! On larger scales, these fixtures become quite dangerous.

According to Which? Magazine, a household LED light fixture will save 60% in energy cost per bulb (Which Nov2017), while also lasting more than 15x as long. Those numbers speak for themselves, so with LEDs getting cheaper to produce every year, and innovations getting more and more creative, they will continue to dominate the markets.

Sources / Read to Find Out More:

1. Proquest.
2. DOI.
3. Edison Tech Center.
4. Physics & Electronics.