What does LED stand for?

In 1927, Russian inventor Oleg Losev set us on the path to better lighting when he created a prototype for the first LED. He used research on electroluminescence to make an early design that wasn’t very efficient (and couldn’t be used practically!)

However, this experiment paved the way for future scientists. Over time, researchers replaced materials and components with more efficient ones until, in 1962, American engineer Nick Holonyak Junior created the first functional LED light. 

Over 60 years later, LEDs have become one of the most commonly used light sources worldwide. Replacing more inefficient models like halogen and incandescent bulbs, LEDs have emerged as the most energy-efficient, cost-effective choice on the market. 

What does LED stand for? 

But what does LED stand for?

The acronym stands for ‘Light-Emitting Diodes’, and this name refers to the way they produce light. The term ‘light-emitting’ describes the process of electroluminescence, where light is produced as a result of electron movement within the semiconductor.

‘Diode’ refers to the device's two-terminal structure, which allows an electric current to flow in one direction. Essentially, when a current passes through an LED, electrons release energy in the form of photons, which we perceive as light! 

What is LED lighting? 

Since their initial production in the 1960s, we have found countless ways to use LEDs. 

You can find LED lighting in smartphones, clock displays, fridges and street lights. But the most common way to use LEDs is in our homes. Before the LED takeover, residential properties mostly relied on incandescent and halogen bulbs for indoor lighting. 

However, these sources are more costly to maintain and less environmentally friendly. Incandescent bulbs have a much shorter lifespan and use harmful substances, like mercury, to produce light. 

Similarly, halogen bulbs burn out quicker than LEDs and convert only about 20% of their energy into light, with the rest emitted as heat. That’s why we now use LEDs in our lamps, kitchen lights and even outdoor lighting. 

What is colour temperature?

We’ve talked about how LEDs produce light, but how do they emit different colours? 

Well, an LED's ability to produce different colours depends on the material inside. Certain substances emit light at different wavelengths, meaning we’ll perceive different colours depending on the materials. 

Red and amber LEDs, for instance, often use aluminium indium gallium phosphorus (AlInGaP) in their material systems, while blue, green, and cyan LEDs use the Indium Gallium Nitride (InGaN) system.

These components allow for what we call ‘colour temperature’. Colour temperature refers to the perceived warmth or coolness of a light. Warm white light creates a cosy, welcoming atmosphere that suits living rooms and bedrooms. 

Cool light, however, is energising. It enhances focus and concentration, meaning it’s often employed in workplaces, offices and hospital settings. Unlike incandescent or halogen bulbs, some LEDs allow users to adjust the colour temperature to their liking. 

Colour temperature is measured in Kelvins (K), and most manufacturers will list the colour temperature of their LED bulbs on their website or packaging. If you’re looking for a colour temperature guide, we’ve compiled a general one for your purchasing needs: 

Colour temperature (Kelvin)	Light colour	Description & mood	Typical use
2700K	Warm white	Comfortable, warm, cosy light	Living room, bedroom
3000K	Bright warm white	Homey light, slightly brighter than warm white	Living spaces, restaurants
3500K	Natural white	Objective, friendly mood	Corridors, offices, showrooms
4000K	Natural white	Brightly appealing light	Bathroom, kitchen, basement, garage
5300K and above	Daylight white	Similar to daylight, with a high proportion of blue	Industrial areas, classrooms, outdoor

What does lumens mean? 

Now that we know how colour temperature is measured, how can we measure the actual light generated by LEDs? Unlike watts, which tell us how much energy a bulb uses, lumens tell us how much light a bulb gives off. 

When shopping for LEDs, you’ll need to pay close attention to the lumens to get the right brightness. If you want to replace a bulb at your work desk, choose one over 1000 lumens for clear and bright illumination. 

But if you need a cosy bedside lamp, select an LED in the range of 600 to 800: you’ll receive an energy-efficient bulb that won’t prevent you from sleeping. 

What is lumen depreciation? 

One of the best features of LEDs is that they’re much less likely to stop working altogether. 

When halogen or incandescent bulbs have reached the end of their lifespan, they turn off completely. There’s no dimming or warning: once they’re off, they’re gone! It’s very uncommon to find this kind of mechanical failure or burnout with LEDs. 

Instead, they undergo a process where the brightness of the LED dims slowly over time, also known as lumen depreciation. Lumen depreciation refers to the gradual reduction in light output, and the L70 rule is a widely recognised standard to describe LED lifespan. 

With ‘L’ referring to luminescence and ‘70’ representing 70% of the original light output, an LED reaches the L70 mark at the end of its useful lifespan. At this point, it only emits 70% of its original light output (indicating a 30% depreciation in lumens). 

But this doesn’t mean the LEDs no longer work! It may signal that the light no longer meets the necessary light levels for its intended application. 

Invest in LEDs with First Lighting!

We hope our comprehensive guide to LEDs has shed more light on the topic! 

This ingenious invention can be used indoors or outdoors, and at First Lighting, we’ve covered all bases. From decking lights to spotlights, flood lights to downlights, we stock a range of industry-leading products designed to uplift your property.