Introduction to LED technology

LED is one of the most important pieces of modern lighting puzzle. Advantages of LED technology are numerous and it keeps evolving. Many believe that LED technology is a “new thing” but the fact is that LED has been around for more than half a century. We can safely say that a small number of people was aware of LEDs in the beginning probably due to its small size (LEDs were used as indicator lights in many devices) and as time passed, their forms became bigger and more people started noticing them. After the initial use as indicators in devices and machines, LEDs were used in lamps, video screens, signs, etc.

How LEDs work

Light in LEDs is a product of electroluminescence which is a phenomenon when material emits light when electric current passes through it. LEDs are solid-state devices that convert the power into a single color light. Because they produce cold light, most of their energy is visible, i.e. they don’t waste generated energy as heat. On the other hand, most of the energy produced by incandescent lamps is not visible and as a result, they produce a significant amount of heat.

LED Technology Explained

In following text, we will try to explain basic principles of LED technology. LED stands for light emitting diode and a diode is the simplest sort of semiconductor device. A semiconductor is a material able to conduct electricity. Majority of semiconductors are made of conductors by adding impurities (a process called ‘doping’). The material used for LEDs is aluminum-gallium-arsenide but without doping, it’s not good enough for conducting current so by doping, it becomes more conductive. Semiconductors with extra electrons is a N-type material (for extra negative particles) and a semiconductor with extra holes is a P-type material (for extra positive particles). A diode is composed of N-type material bonded to P-type material with electrodes on both ends. This type of connection enables electricity to be conducted in only one direction. The way electrons and holes interact in this setting creates light. Photons, which are basic units of light, are released as a result from electron movement. Free electrons movement can happen in any type of diode but it’s composition determines the frequency. Some diodes emit infrared light which is not visible to the eye (remote controls) but others produce light which is visible to human eye. Depending on the materials used for the diode, it can produce infrared, ultraviolet and all other colors.

LEDs are especially designed to release a large number of photons and then housed in a bulb in order to beam the light in certain direction. Since they don’t have a filament which eventually burns out, and their casing makes them really durable, it’s no wonder they take advantage over standard, old-fashioned incandescent light bulbs. However, the main benefit of LEDs is their efficiency. They use a high percentage of generated energy to produce light which considerably cuts down the required power. If we were to compare LEDs and incandescent light per watts, LEDs output more lumens per unit. And last but not least, their lifespan goes up to 100,000 hours. Incredible!

Future of LED

Even though LED bulbs are not yet widespread among households all over the world, the benefits are undeniable. So far, the biggest obstacle was the price but if we look at it long term, the initial cost is reasonable. If we take a look at yearly power consumption of different light bulbs, 60-watt incandescent bulb takes the lead with $300 a year providing 800 lumens of light; the second place goes to its 15-watt CFL (compact fluorescent) equivalent with about $75 cost and finally LED bulb, with 8-watt consumption, $30 cost and more than 50,000 operation time. There are 8,760 hours in a year, so how long will the LED bulb last in an average home?

Aside from the cost, there is room for improvement in other aspects of LED lighting. LEDs are prone to damage at high temperatures and subsequently too much current. It causes an irreversible meltdown. One more thing we’re not accustomed to is light being cool instead of warm, yellowish light of incandescent lights.

Over the decades, the development of LED technology has come a long way. Just think of TVs. Remember the days when a TV set was big and heavy? Well, those days are gone and from the looks of it, television sets will become even thinner and lighter. The thin, LCD TVs use LED instead of fluorescent tubes to shine light from the back. Further development of the technology could create large screen TVs with only LED lights in side thus making them barely an inch thick.

Now, we can only sit and wait for new wonders of LED.