How do LED lights work?

All human-made things are always subject to change and evolution. This applies to all discoveries and inventions; the only difference from one invention to another is the time it takes to develop. When it comes to lighting, we have witnessed a tremendous amount of innovations and improvement from the origin of the bulb to the present lighting systems. 

The innovations brought many colorful things to our life and became more efficient and economical in nature. When talking about nature, improved LED lights are more eco-friendly than incandescent. The environment-friendly, efficient, and more durable LED lights are the number one choice for many people nowadays; thus, we can see LED lights in homes, offices, street lights, and all other places. 

However, several people are still skeptical about LED lights, and they are using other bulbs such as incandescent and CFLs. The reason can be because of a lack of awareness, or many people think it costs more than the different options available in the market. But is that true? Are you going to save money by purchasing the LED lights, or are you paying extra money from your pocket? Do LED lights help in providing more offers or not? And along with this, you have many other questions, including how it works and why it is beneficial to us.  

Hence today, let us try to know more about the LED lights in detail. 

What is the LED light?

Okay, first things first. The initial question for many people is what is LED? Well, LED stands for Light Emitting Diode. It is a semiconductor source of light that produces light when power flows through it. In short, they are the means through which light-emitting diodes generate light. 

At the current moment, there is nothing superior to LED lights in the lighting industry. If you are wondering how the answer is, it lasts longer than all other fixtures. The LEDs offer a massive number of life span ranging from 30,000 hours to 100,000 hours! It also houses numerous benefits, including its super efficiency and many other things which we will discuss in the latter part of this article. 

How Do LED Lights Work?

The knowledge about the diode is mandatory if you want to know about LED. The diodes are the simplest form of a semiconductor device. A semiconductor is made with a material with varying nature of conducting electrical current. 

In LEDs, the conductor material will generally be aluminum-gallium-arsenide (AlGaAs). It facilitates the atoms to bond perfectly with neighbors, and they leave no free electrons to conduct electric current. 

Type N

The type N materials are those where they have extra electrons because they are extra negatively charged particles. In this type of material, free electrons travel from a negatively charged area to a positive side. 

Type P

The same way type-N comes with extra charged negative particles. Type P materials come with the excess positively charged particles. The semiconductor, which is available with an extra hole, is known as Type materials. In this type, electrons move from hole to hole and travel from the negatively charged area to the positive side. Consequently, it looks like the holes itself running from negatively charged parts to positively charged parts. 

The diode comprises a section of P-type material bounded to a part of N-type material with electrodes on either side. This P-type arrangement results in electricity flowing in only a single direction. Whenever there is no voltage applied to a diode, electrons of N-type particles fill holes from P-type particles along with the junction between the layers. This process will result in creating a depletion zone. 

In this zone, the semiconductor is returned to its original insulating condition, and all the holes get filled; consequently, there are no empty spaces available for electrons or free electrons. This process can’t be able to generate electricity flow. 

To come out of this depletion zone, one has to make electrons move from the N-type area to the P-type place, and holes move in the reverse direction. To make this possible, you need to connect the P-type end of the diode to the positive end of a circuit and N-side to the negative end. This will cause free electrons present in N-type particles to repel by the negative electrode and attract to the positive electrode. 

The holes are available in P-type material travel the other way around. Whenever there is a fluctuation in voltage between the electrons is high enough, the electrons present in the depletion zone are boosted from their holes and start to move again. Once the depletion zone disappears, charge travels across the diode. The interaction between holes and electrons in this arrangement generates the light. 

The catch is if you try to run power the other way by connecting the P-type side to the negative end of the circuit and N-type end to the positive end, the current will not flow. 

How does a diode produce light?

As we already know, light is a form of energy, and an atom can produce it. It consists of numerous small particle-like packets with momentum and energy but the absence of mass. This type of particle is known as photons, which are the basic unit of light. 

The moving electrons release the photons. In an atom, electrons move around the nucleus. The electrons present in different orbitals have different levels of energies. Typically, the electrons with high energy travel in orbitals farther from the nucleus. 

An electron needs something to enhance its energy level to move from a lower to a higher orbital. When an electron drops from a more top orbital, it releases energy. It is released in the form of a photon. A higher frequency is caused by the release of an increased energy drop.

As we already discussed, free electrons traveling across a diode may fall into vacant holes from P-type. This process comprises a drop from the conduction band to fewer orbits. Thus electrons produce energy in terms of photons. This process can happen in any diode, but you could only see the photons only when the diode is made of specific material. 

The atoms are arranged in standard silicon diodes so that the dropping of electrons happens in a relatively short distance. So, the frequency of the photon becomes very low, and it becomes invisible to humans. That means it is in the infrared portion. The infrared LEDs are vital because it is used in many things, including the TV remote. 

The wider gap between the lower orbitals and the conduction band makes the materials that we can see in digital clocks. They are called VLEDs or Visible Light Emitting Diodes. The frequency of photons is decided by the gap and its size in the conductor band. That means this determines the color of the LED. The VLEDs are most famous because of their long-lasting character and compact size. The materials used to make the LED light determines the shining level in the lights, such as ultraviolet, infrared, and all other colors. 

LED materials and light colors

The usage of LEDs is widespread, and as a result, you can see this from the digital clock to light the entire home. There are broadly two types of material used to produce LED products. 

LED Silicone Materials

The silicone materials are the lifeblood of any LED device, which provides a high brightness level. These are typically optically reflective. 

LED Lead-frames

These are the metal structures we can see inside the chip package that carries signals from the die to the outside. And this needs an electrolytic finish to produce desired brightness, reflectivity, and wire bonding. 

Light colors

Blue LED

The first blue LED was made in 1972 at Stanford University. The blue light produced from this type of LED is used in varieties of devices. You can find this often in consumer electronic devices as an indicator light. You could see the usage of this in dental clinics and other fields too. Nowadays, it is used mainly for aesthetic reasons. 

White LEDs

The next level of progress in the field of LED is made with the invention of white LEDs. Before LEDs were restricted only to indicators, emergency lights, and displays. With the advent of white light LEDs, you can witness them in almost all lighting applications, including street lighting, home lighting, and floodlighting. 

Naturally, a LED is not able to produce white light. To make this possible, there are three methods. This can be done using wavelength conversion, Homo-epitaxial ZnSe, and color mixing technologies. 

Ultraviolet

AlGaN, or popularly known as Aluminum gallium nitride of varying Al/Ga fraction, can be used to produce the quantum and cladding layers for UV or ultraviolet LEDs.These LEDs are yet to reach their highest level of efficiency and technical maturity. 

RGB systems

The LEDs with RGB modes are gaining more popularity because you can choose the color you want at any given time. In this system, the combination of Red, Green, and Blue sources are used to generate white light needs and control color blending. Due to the LEDs having different patterns of emitting the color balance may change as per the angle of view. 

Phosphor-based LEDs

Under this process, coating LEDs of one color with phosphor of varieties of colors to generate the white light. In most cases, a blue LED is used to produce white light. 

Types Of LED

We can mainly differentiate the LEDs into two types, and they are explained in the below section. 

LED Indicator

The term indicator means the use of a light source to be viewed directly as a luminous object. It includes the self-luminousness in signals, signs, and indicators on several electronic materials.

LED Illuminator 

It refers to light sources’ usage to view other things by the reflection of light on those objects. It includes the regular lights we can see in most rooms, homes, and street lights. 

LED Light Bulbs vs. CFLs and Incandescent

For a long when it comes to the lighting industry, there was the only winner- incandescent. The reason is there was no other form of bulbs to compete against it. But after some time, the Compact Fluorescent Light or commonly known as CFL light came into the screen. It offered efficient and cheaper lighting options to the world. The LEDs are relatively new to this race, and at the initial stage, it was quite expensive, and they have been dimmed. 

But the scenes of the race have changed in the past five years or so. Now there are numerous manufacturers of LED lights in the market with their efficient, energy, and money-saving lights. The one more thing which makes a conscious person about the environment to opt is its eco-friendliness when it’s discarded. The comparison will help you understand why LEDs are the current champion when it comes to lighting. 

Heat

Heat is a significant aspect of lighting, especially if you are going to purchase a large number of bulbs for your home or premises. If you are going to install numerous bulbs in your building, the heat can become a cause for fire accidents. That doesn’t mean only for significant buildings, factories, or offices it applies, even for home, the excess heat can become a villain to its safety. Thus, regardless of installation size, heat should be given topmost priority. 

So, incandescents are the number one culprit when it comes to producing the heat. The next place goes to CFL, and at last, it is LEDs place. The first two types of bulbs utilize the power and release more heat than light. Consequently, both will become hotter compared to LEDs. This is the primary reason for the inefficiency of CFL and incandescents. 

The 100W LED bulbs will burn at 87.2 F, CFL lights burn at 179.2 F, and incandescent bulbs burn at 335.4 F. It is evident that approximately LEDs are four times more efficient than incandescent and two times efficient than CFL only considering the heat. 

Brightness

We don’t think about the fire accident possibilities, heat production, and other things when thinking about light. We are mostly concerned about the brightness light can provide. The brightness of a light is measured in terms of lumens (lm). 

The LED 10W light produces 800 lumens, a CFL of 13W light will provide approximately 800 lumens, and a typical incandescent bulb can produce 900 to 1000 lumens with 75W capacity. The calculation of efficient lights is straightforward. You can determine the same by dividing the output by wattage required for a bulb to produce the lumens. In this example, you can find out the incandescent provides approx 14 lm/W, CFL with 65l/W, and a LED will provide 85 lm/W. That means approximately you need to spend just $3.7 annually if you run the light on an average of 8 hours per day for the entire year.  

Life span

The average lifespan of a light determines the cost-effectiveness of the same. There is no doubt that incandescents cost less while purchasing the bulb, but can we say it is most efficient? The answer is no. The reason is you are paying more dollars in your monthly electricity bill. 

LEDs are popularly known for their long life span. They offer a life expectancy of over 50,000 hours as per the theory. But in reality, it runs even more than that. If you compare the life expectancy of the other two types, the difference is enormous. a CFL can burn up to 8,000 hours, and when it comes to incandescents, it is just 750 hours. 

This is the main reason why large scale commercials are replacing their CFL or incandescents with LEDs. It significantly saves money because you no need to replace a considerable number of bulbs in a year if you install LEDs. 

Impact of environment

The need for using eco-friendly materials is the need of the hour in the current situation. From an environmental perspective, CFL is the most dangerous light. It harms nature when it is in usage, as well as when it is discarded. You cannot dispose of the CFL bulb like normal LED or incandescents, the mercury content available in CFL contaminates soil and water sources when it is discarded scientifically. CFLs also emit the dangerous gas – greenhouse (both when using and after dropping). 

You are free from these worries if you have LED and incandescents. Furthermore, many components of LED can be recycled; however, since it provides more life, people don’t care about recycling those parts often. 

Advantages of LED

Energy Efficient 

The LEDs are more efficient than other types of lights because they consume less amount of energy. Unlike other bulbs, LED lights convert the maximum amount of power for light than releasing the heat. 

Environmental protection

They are safer both while using the lights and also after discarding the lights for the environment. 

Color

The most significant advantage of LED is you can get multiple colors. In the new smart LEDs, you can get numerous colors in a single bulb!

Size

You will get the LED lights in different sizes to cater to all your needs. The shapes and sizes are multiple, and you can’t get this many options in other types of bulbs. 

Lifespan

The LED offers a long-lasting life span of over 50,000 hours, which is approx. 65 times more than regular incandescent bulbs and six times than CFL. 

Disadvantages of LED

Temperature dependence

The LEDs are dependent mainly on the operating temperature. The high-temperature current can cause damage to the circuits. 

Color rendition

The LED is also subject to color rendition. 

Light pollution

Of course, LED is better than other forms of lights, and it still causes light pollution.

Thermal runaway

Since it is subject to temperature dependence, LEDs can cause thermal runaway with high temperatures. 

How to choose good LED lights?

Many people get confused while selecting the LED bulbs. It is not a surprising thing, because the varieties of LED lights are numerous. You can get the best LED if you follow the below items.

1. Install where you run the light most

No doubt, considering the initial investment, it is expensive. Hence, if you are short of budget to replace all your bulbs, install it where you use the most. This also makes you get your savings soon. That means, if you are installing the LED in a place where you hardly use it, it will take years together to recover your initial money in terms of energy savings. 

2. Look for lumens instead of watts

 The continuous usage of incandescent bulbs made us shop for the high wattage bulbs when we require bright lights. The reason is we know how much brightness we can expect from 150,100 and 60 wattage bulbs. But as we went through earlier, the brightness level is determined by lumens and not by wattages. 

The LEDs also come with wattage descriptions on the package, but it is impossible to determine the brightness of LED and incandescent by comparing the watts. You can’t get any uniform method to compare both types of bulbs. If you are looking to get the brightness level of a 150 wattage incandescent bulb, you need to purchase an LED of 26oo lm (26-28 watts). 

3. Choose your favorite color

It is common to get bored with the monotonous color of your light. But the good thing about LEDs is you can get numerous options to choose your favorite color ranging from warmer yellow-white, bluish-white, whiter white, and many.

You can check the color of your light by checking the package of the bulb. You can also find kelvin numbers on the box. The higher the Kelvin number it produces blue light. The lower number of Kelvin means you can get warmer color light. 

4. Shape

The LED lights available with numerous shapes that you are unfamiliar with. You could find the form of globes, spotlights, spiral bulbs, floodlights, candle shapes, etc. You need to decide which light suits your space before purchasing.

Apart from all these, you will get other choices in terms of prices, brands, etc.

Conclusion

It is evident that considering all the aspects of the lighting system, there is no better alternative to LEDs. It is more efficient, power saving, safer, and environment friendly than LED lights. The wide range of options it is rendering to its consumers it is no brainer to replace your incandescent or CFL with LED lights. The usage of LED lights is present in all kinds of equipment in modern days, including digital clocks, remote to street lights.