Infrared Emitting Diodes, or IREDs as they are popularly known, are solid-state light sources emitting in the near-infrared part of the spectrum. Just like all other light sources, they have their advantages and disadvantages which make them suitable for different functions.
Advantages
While there are different types of infrared light-emitting diodes out there, each one of these types has its advantages. These are the factors that give them an edge over other light-emitting diodes and what makes them suitable for their designated applications.
● Long Lifespan
Compared to the conventional incandescent lamps, infrared LEDs last significantly longer. The lifetime of the conventional incandescent lamps ranges between 3,000 and 4,000 hours. Infrared LEDs, on the other hand, have an ETTF (Estimated Time To Failure) of about 100,000 hours. This means that if you leave your infrared LED to work for five hours a day, you’ll still have it functioning well fifty years down the line, provided no external factors are involved.
● Eco-Friendly
With scientists predicting that climate change might render our beautiful earth inhabitable in the future, we need to start looking for ways to save the earth. Infrared LEDs can play a role in this. Please note that we’re not suggesting that infrared LEDs are the ultimate solution to climate change, but they do play a part in caring for the environment. Unlike the conventional incandescent bulbs and fluorescent lamps, LEDs use a different principle to emit light. They do not rely on filaments that will burn out, become heated, or disperse toxic gas which might be dangerous for the environment. Instead, LEDs are more stable and can therefore withstand an external shock.
● Energy Efficient & Low Cost
Most LEDs are designed to operate with 12v but some can go up to 24v. When you take this, plus the fact that they produce more light for every watt compared to incandescent bulbs you’ll see that they are more energy-efficient and generally require lower operating costs. In fact, studies have shown that LEDs use up to 80% less power which is quite staggering. To put it into context, the cost of running one incandescent bulb is about four times that of standard LEDs. It is worth pointing out that LEDs are understandably more expensive than conventional bulbs. However, the price gap is offset by the incredible power saving. Again, to put some context, suppose a LED requires 15W to reach a particular level of luminance, it would take up to 150W for a conventional incandescent lamp to reach the same level of luminance.
● Wide Range of Applications
For a long time, LEDs were mainly used for numeric displays and indicator lights. But with evolution and human beings looking for solutions to everyday problems, the applications of LEDs have evolved to greater disciplines. Some of the different places LED lights are used include architectural lights, exit signs, accent lights, task lights, traffic lights, signage, cove lighting, wall sconces, outdoor lighting, and downlighting among others.
● Environmental Adaptability
LEDs have a decent operating temperature window of between -40℃ and +85℃, and humidity below 65%. This means that LEDs can be used in different environments including some relatively harsh conditions.
Disadvantages
Nothing is ever perfect and just like other light-producing objects, LEDs too have their weaknesses.
● Bad Color Revivification
LEDs are generally known to have a poor color rendering index. Their color reversion isn’t good either, especially when compared to incandescent bulbs. The lighting quality of LEDs also doesn’t match incandescent bulbs which have a CRI of 100% while white LEDs provide color rendering indices between 70% and 85%. Nevertheless, the CRI can be boosted to about 90% with the improvement of phosphors and the technological upgrade of LED materials.
● Single LEDs Have Low Power
One Sticking point with LEDs is the fact that one has to connect multiple ones in parallel to get the best illumination as seen in automobile backlights. The knock-on effect of this is that it increases costs since one will be forced to buy multiple infrared light emitting diodes if they want to achieve a higher light intensity.
● Yellow Ring Phenomenon
This comes from the bizarre yellow rings that appear in white LEDs most of the time when illuminated. The things are brought about by the immature process of white light LEDs and the error experienced when configuring the reflective cup and lens. These rings are usually very hard to eliminate leaving the user to have to contend with them. For instance, take the blue light LED. It generates white light by activating a mixture of YAG phosphor and green or red phosphor. If after activating YAG phosphor, the blue light LED emits white light with a “yellow ring”, one may add green light phosphor with a wavelength of between 500 nm and 530 nm to counteract the unwanted yellow light. Similarly, if after activating YAG phosphor, the blue light LED emits white light with a “blue ring”, one can add red light phosphor without sulfide to counteract the unwanted blue light. These methods can regulate not only the color coordinates but also the color temperature of LEDs, without affecting the lifespan of the LEDs.
● Short Illumination Range
Another sticking point with LEDs is the fact that they have an annoyingly short illumination range. They emit scattered light thus providing an illumination range of only tens of meters. This limits them to short range applications but there is hope that with everyday technological discoveries, the LED illumination range will expand.
● Heat Dissipation
The heat generated by the acting light emitting chip for the LED has to be absorbed to maintain normal working temperature. This is necessary to prevent overheating or damaging the chip. Industry players such as Excelitas strive to develop more efficient heat-dissipating materials.
Despite having a few imperfections, an infrared light emitting diode still has the edge over conventional incandescent lamps which are the closest substitutes. From a compact size, long lifespan, energy efficiency, and durability they have everything it takes to be a next generation light source.
