What Spectrum of Light do LEDs Produce?

There are many various types of light sources, ranging from the common incandescent bulb to more modern innovations like LED. Yet not all of these many light sources are created equal.

Beyond only creating light, each of them has distinctive qualities, one of which being the colours they emit. This can also be referred to as each person's unique light spectrum.

The colour temperature of an LED determines the spectrum of light it emits. A 6000K LED's spectral distribution will be different from that of a 3000K LED's. A 6000K LED will mostly emit blue and green light, whereas a 3000K LED will create more warm colours like orange and yellow.

We shall hereafter refer to 4000K as the base for LED light colour and consequently its light spectrum as the base form since a totally natural LED without any additions or alterations has a light colour of around that.

Spectral Distribution of LEDs at 4000 K

It only seems sense that we start with the 4000K LED as it forms the fundamental foundation of the spectral diagram.

The spectrum at 4000K, as seen in the image below, leans heavily towards the blue end while also emitting very little red and green light. As blue light is the primary constituent of cooler lights, this is what gives the LED its cool white colour.

The fact that LEDs are made up of several diodes is the primary reason why they are cool white in the first place. They are made in such a way that they use RGB (red, green, and blue) diodes to produce white light, which in this instance just defaults to 4000K.

The alternative method of making LEDs involves utilising largely (if not exclusively) blue LED diodes and then coating them with a phosphor-based solution to straighten out the curve.

As the blue light output is the primary source of light in that LED structure, this is what typically results in abnormally high peaks in the production of blue light.

When you have light in every colour, or in every wavelength, as you can more exactly call it, they all converge together to make white light, which is how it even works in the first place.

Later on in the comparison, you will see how much the diagrams vary based on how much blue and red they emit, which is connected to their colour temperature.

3000K LED spectrum

After those with a 4000K colour temperature, 3000K LEDs are perhaps the most widely utilised, mostly because of the pleasant yellowish tint they emit.

We should first examine what distinguishes 3000K and 4000K LEDs from one another before delving further into the spectrum and its specifics. Because we already know that 4000K is the starting point, they must have adjusted it in some manner to reach a bright colour of 3000K, correct? It is accurate.

The presence of phosphor is what differentiates a 3000K from a 4000K. The phosphor is simply applied on top of each of the LED diodes, as seen in this figure, to add it.

Here is a great illustration of how they utilise the phosfor to warm up the light colour. Although it's not the main goal, when executed in this manner, it has that impact.

The only genuine goal of this is to just balance out the spectrum for the LED. This makes sense since you can see how the 4000K graphic has a large peak in the colour blue, but the rest is at best average.

5000K+ LED spectrum

Now that we are aware of how to produce warmer light temperatures, how are 5000K and below temperatures produced? This is quite intriguing since, depending on how you look at it, it differs from the way you build the 3000K ones only slightly.

These differences are relevant during the production process. Red, green, and blue diodes have always been balanced in order to produce white light in all prior light colours. While it's a little different for anything 5000K and higher.

For them, you would intentionally design an imbalanced LED diode. It means that the individual RGB diodes would intentionally be distributed unevenly in terms of quantity and/or intensity.

They balance the RGB diodes such that the more blue they favour in the RGB mix, the cooler you want the light to be perceived to be. This depends on how high you go on the Kelvin scale. In other words, they just let the blue overrun the red and green the higher you go, making the blue and bluer colours more prominent in the light colour.

This may also be done in a method that adds an additional set of blue diodes all at once, generating something new termed RGBB, rather than increasing the proportion of blue diodes in the RGB mixture.

Because RGBB has the potential to maintain the purity of the output of ordinary white light, it would be preferred over pure RGB.

This is due to the fact that an RGBB system merely adds more blue to the original RGB system, maintaining the harmony of the original RGBs.

This explains why red and green are relatively low on the spectrum chart whereas blue jumps dramatically higher. Along with making items appear somewhat blue, this also makes the light appear to be quite blue.

Whole-spectrum LEDs

The full spectrum LED is a different sort of LED from the standard LED structure. The spectral curve of sunlight is intended to be replicated by the construction of the full spectrum LED.

To achieve this, a phosphor combination of various colours is employed instead of the more typically used yellowish phosphor mixture.

The LED emits more colours as a result, more nearly resembling the sunlight than it would without.

Use in grow lights is the main reason for having a light source that can mimic sunshine. Grow lights are light sources that support plant growth by giving plants enough sunshine-like light when they get insufficient or no natural sunlight.

They are primarily utilised in facilities that are dependent on food production since high yields are crucial. Yet, because of the growing demand for grow lights designed for the house, they are now beginning to appear in backyard gardens.

Comparison of LEDs at various Kelvin temperatures (K)

Although there aren't many distinctions between these LEDs when compared, there are a few things that one would think are significant.

The fundamental distinction between these various light sources is that they emit light that might elicit various psychological reactions and emotions, making them unsuitable for the same uses.

A 4000K LED is better suitable for spaces where mental alertness and concentration are priorities, like offices, whereas a 3000K LED is much more suited for homes and spaces where comfort is a concern.

In the same way, though, using anything 5000K+ is rare, particularly when it comes to interior design or anything else for that matter. Aquariums are one typical application for 10000K, but other than that, there aren't many other places it may be employed.

Yet, there is one crucial distinction to be made between 3000K and 4000K, and it has to do with technological matters. If you compare the energy efficiency to the actual light output, that is the factor.

It is usual practise to measure many types of light sources using the Lumen/Watt unit, where a lumen represents the "amount of light" that a light source emits and a watt represents the energy that we have supplied to the LED.

With this in mind, it's noteworthy to note that a natural LED with a light colour of 4000K will be more efficient (lumens/watt) than an LED with a light colour of 3000K.

This is due to the presence of phosphor in the 3000K LED. This is so that the phosphor can effectively absorb some of the overall light that the LED emits.

This makes sense since, as we have already seen with the retrofit LED bulb, the phosphor is physically covering all of the many little diodes.

Summary

Despite the fact that LEDs are typically cold, they can generate light over the whole visible light spectrum.

Warmer LEDs need to be coated with phosphor to generate warmer light, therefore cool LEDs are around 5% more efficient in converting energy into light.