LED Lights: How They Work

If you’ve installed or seen this lighting system, you must have wondered how LED lights work.

These impressive lights provide highly efficient lighting and last way longer than your typical incandescent or fluorescent lights.

This article explains how they work and why they’re a great lighting choice. 

The Working Principle of LEDs

Now the principle of action of an LED light bulb is electroluminescence.

The bulb uses a p-n junction diode that’s made up of two lead semiconductor light sources.

When activated, the diode emits light. 

Under the appropriate voltage, electrons get excited and combine with electron holes within the bulb to release energy.

This energy is in the form of photons equivalent to the light produced.

And what’s interesting is that the light color is proportional to the energy band gap of the semiconductor. 

When current passes through the LED, holes in p-type regions move toward the n-type region.

On the other hand, electrons in the n-type move toward the p-type region.

The injected recombines the two, thus creating an energy difference. Then the energy gets released as light. 

How Do LED Bulbs Work?

LED lights use aluminum gallium arsenide (AIGaAs).

In its free state, the electrons in the material get strongly bonded.

Thus, it inhibits the conduction and free movement of electrons. 

Additionally, doping, a process of intentionally adding impurities, destabilizes the balance.

As a result, some of the electrons in the material get freed up.

Adding the impurities, it enhances the conductivity of the material. 

So the electrons move from the anode to the cathode terminals in the n-type semiconductor under the influence of electric current.

And vice versa for the p-type materials. 

Consequently, in LED bulbs, energy production is proportional to the amount of photons.

Electrons require energy to shift from the shorter to the longer orbit.

On the other hand, electrons moving from higher orbitals to lower orbitals release energy.

And this energy takes the form of photons or light. 

In p-type doping, electrons move by falling from a higher orbit to a lower orbit. In doing so, they produce energy.

Interestingly, the disturbance between the orbitals determines the intensity of the emission of photons and, by extension, the amount of light.

Additionally, the amount of light emitted depends on the type of semiconductor used. 

How Does a LED Produce Different Colors?

See, LED lights produce photons at a specific wavelength.

LEDs employ materials that can handle current, humidity, and heat to do this.

For instance, LEDs can use Aluminum Indium Gallium Phosphide (AlInGaP) to produce red and amber colors. 

On the other hand, LEDs with Indium Gallium Nitride (InGaN) emit the colors blue, green, and cyan (greenish-blue).

In some cases, LED lights produce green-yellow and yellow colors.

Such LED lights consist of a combination of AllnGaP and InGaN.

However, doesn’t the light spectrum consist of many more colors than those mentioned above, one might argue?

Yes, that’s true.

And to produce the many different color fragments, manufacturers design different forms of LED lights. 

For example, there are multi-chip LEDs, also known as lighting fixtures.

These comprise two or three diodes and thus provide two or three color wavelengths.

As a result, they can produce millions of color shades.

Also, they’re much brighter, although you can regulate the intensities of the emitted light. 

What’s remarkable is that the colors are all from the same semiconductor materials.

Regulating the amount of electric current through the semiconductor significantly affects the number of photons emitted and, thus, the amount of light.    

What Color Is In a LED Bulb?

The color of LED lights depends on the wavelength of the light that the material used in its design.

On one end are the warm lights, typically yellow, orange, and red colors.

Then on the other end is the cool colors, typically purple, blue, and greenish.

Thus, you may notice different types of LED light colors.

But in general, the type of semiconductor used is the critical determinant of these colors.  

(Caption: green LED light color)

How Long Do LED Lights Last?

Undoubtedly, LED lights have a longer lifespan of 100,000 to 200,000 hours.

So, LED lights can last up to 20 years compared to other light sources.

In fact, under the right environment, they can even last longer. 

As you can imagine, these lights have various features contributing to their long lifespan. For example, 

First, they have higher luminous decay (gradual reduction of lumen flux or photons).

That means instead of an abrupt reduction of light output, the brightness in LED lights declines gradually, so the bulb dims or burns out slower. 

Also, they have a high level of brightness and intensity under a small amount of current and voltage.

Thus, they’re about five times more energy efficient than other artificial light sources. 

Additionally, because they don’t have infrared, they radiate less heat.

Therefore, virtually no damage to the components due to excess heat can occur.    

Furthermore, LEDs have no filaments. Instead, they use light-emitting diodes to create light.

These are sturdy and can withstand harsh conditions better than other lights.

Also, the chances of damage due to handling are slim.  

Dimmer switch

(Caption: Dimmer switch)

Can You Use LED Bulbs in Other Types of Lighting?

Unlike in the past, today, manufacturers design these bulbs for use in different types of lighting, as long as the socket is the same size and type.

Otherwise, the bulbs won’t fit. 

Most importantly, the bulbs’ wattage should never exceed what’s recommended for the fixture.

A lower wattage should be fine because LED lights require fewer watts than incandescent bulbs to produce the same light output.

Therefore, you can use a LED bulb with less wattage than the other light fixture. It’s cost-effective. 

So, yes, you can use LED bulbs in other types of lighting. Ensure the LED bulb’s base, shape, and wattage are compatible with your lighting fixture. 


What Makes LED Lights Change Color?

The intensity of light and color depends on the type of semiconductor used. In turn, it determines the wavelength of the light the LED emits within the light spectrum.  

Why Do LED Lights Last So Long?

LED bulbs have low energy requirements, lack movable internal parts, and low heat emissions.

And all these factors enhance these bulbs’ lifespan. 

What Are the Advantages of LED Lights?

The advantages of LED lights include: 

  • They’re easy to install
  • They have a longer lifespan
  • They’re energy-efficient
  • They have low radiant heat

What Are the Disadvantages of LED Lights?

Impressive as they are, LED lights do have some disadvantages, which include:

A slight increase in the amount of voltage can easily damage them.

Their temperature depends on the radiant output power and wavelength.

Thus, you can’t use them to warm a room as they have lower heat emissions. 


That’s it on LED lights, how they work. As we’ve seen, the design of these lights ensures they can meet varying lighting needs.

For example, using semiconductors of different chemical elements allows them to produce a broader range of light shades.

Also, their lifespan and efficiency make them great lighting systems.