Advantages and Disadvantages of LED

The Full form of LED is Light Emitting Diode. It is an example of a semiconductor diode. It is a highly doped p-n junction that emits spontaneous radiation under the forward bias.

Ancient LED techniques were based on Gallium arsenide phosphide (GaAsP), Aluminum gallium arsenide, and Gallium Phosphide.

Construction of LED

The structure of the LED is made up of three semiconductors layers covered over the substrate. The P-type layer is at the top, and N-type region is at the bottom, and the central layer is known as the active region of the LED. P regions have holes in the majority, and the N-type consists of large numbers of electrons. The middle layer, which is the active region, is comprised of both electrons and holes. The N-type region is highly doped in comparison with the P-type semiconductor. Deposition of the P-type is above the N layer due to the electron-hole pair recombination towards the p area, and the p region is the present upward surface of the LED. The photons (light energy packets) are released due to the electron-hole pair combination seen from the area. If the P region is kept below the region, the Light released from the LED will not be seen. The p-type semiconductor is the thin metallic layer that gives the anode connections, and the N-type is covered with a thin gold layer that gives the cathode connections.

Types of LED

LED can be produced in various designs, shapes, and sizes according to the needs. Some of the most widely used LEDs are:

1. Through Hole LEDs

Through Hole, LEDs are also referred to as leaded LEDs, and it is connected to the circuit board with two wires. It is used in components that undergo extreme temperature variations and mechanical stress. Significant features of the LED are it is budget-friendly and do not provide backward illumination.

2. Surface Mounted Diode LEDs

LEDs are extremely popular for lighting and widely used in domestic households and offices. It is smaller in size, making it a suitable choice for space-limited circuit boards. It is present in different colors and packaging types. It has more numbers of pins compared to through-hole LEDs. Some features are lightweight, with less capacitance and inductance; hence, it becomes Ideal for RF applications.

3. High- Brightness LEDs

High light intensity or High Brightness LEDs are the newest inorganic LEDs. It requires controlled electric current and accurate power dissipation for maximum light output. It is widely applied in signage, project displays, and architectural illumination.

4. Chip on Board LEDs

It is a newly emerged LED and provides good benefits over the existing ones. Some of the features include Chip on Board LEDs because it is more efficient than SMD and takes less power. It comprises multiple chips directly connected to the substrate to do a single module. When these LEDs are packed together, they look like a lightning panel rather than isolated lights, as in the closely surface-mounted LEDs.

5. RGB LEDs

It comprises different colors in one package. These multiple colors include Blue, Red, and Green. With the combination of these colors, it can produce almost every color. To produce colors of different intensities of Red, Green, and Blue LEDs greatly differs. The Pulse width Modulation signal administers the Light intensity of these LEDs. Due to the tightly packaging, the human eye can see only the final colors it produces after combining three varied colors.

6. Graphene LEDs

In this kind of LED, the filament of the LED Light bulb is layered with Graphene. It is believed they are 10% more efficient than other preferred standard LEDs. Some of the features include are it has more life span, being cheap, and being easy to produce. It will have a great advantage if the graphene LEDs are replaced with regular LEDs at the commercial and industrial scale.

7. Seven Segment LEDs and Alphanumeric LEDs

Seven Segment LEDs are the digital displays module that represents the numerical data. These LEDs are placed in numerical shapes. They are even called seven-segment indicators or seven-segment displays. The alphanumeric LEDs can exhibit both alphabets and numeric characters.

8. Organic Light Emitting Diode (O-LEDs)

The composition of this LED can be easily understood from the name, and it suggests that it was made up of organic substances. The regular emitting diode is composed of inorganic semiconductors and has varying levels of dopings. LED displays are built using narrow sheets that form a diffused light area. It is a narrow film material that is printed over the glass substrate. Organic technology usage is increasing multifold.

9. Dimmer Switches LEDs

This type of LED is seen in dimmer switches and other conventional bulbs, and the performance of dimmer switches LED is better than dimmer switch bulbs. This is the main cause why standard bulbs are being replaced with dimer switch bulbs.

Applications of LED

• Display Panels use LED Lights: They can be commonly seen in dynamic, decorative displays, stadium displays, and dynamic message signs. These slim and lightweight displays generally showcase schedule charts at airports and railways.
• LED indicators can be easily seen in several industries, and these displays show the status of electronic devices. It can also be observed in calculators, digital watches, and multimeters.
• Its application is visible in traffic and automotive brake lights due to clear visibility in broad daylight, fast switching time, and long shelf life. Its application in the brake system has been proven to be greatly advantageous as it has a fast rise time and improves safety.
• Their temporary applications can also be seen in LED art, throwies, and glowsticks. Throwies are tiny LED devices applied in various types of street art.

Advantages of the LED

LEDs are the most preferred light sources compared to other ones. Some of the other advantages of LED are:

• One of the primary reasons for the massive usage of LED lights is their efficiency of the LED lights. Incandescent bulbs require filament to illuminate the bulb, and the filament is supposed to be at its warmest. It leads to huge electricity consumption, and much power gets wasted in this process. In the case of LED bulbs, the maximum electricity is used to illuminate the bulb, and a very minimal amount of electricity is used for heat production. It turns LED into a cost-effective bulb that cuts down the electricity bill.
• LEDs do not possess filament to compare to incandescent bulbs that burn out quickly, and therefore, shelf life is shorter compared to other bulbs.
• LEDs possess a longer period due to their thermal management properties. LEDs are suited with heat sinks by which they absorb the heat generated by the bulb and dissipate it outside.
• It is more efficient in converting electricity into visible Light, and its output is higher than other light sources. For example, a normal 60-watt produces 750-900 lumens, and the same output can be produced using 6-8 watts bulbs.
• With climate change becoming a grave concern, environmentally aware people are turning to eco-friendly methods of light sources. Mercury is used as a crucial part of the manufacturing of incandescent and Light fluorescent sources. When the shelf life of conventional sources of Light is about to end, it requires extra care to dispose of them. In the case of LED bulbs, it does not require special treatment in disposing of them as disposal of the LED does not harm nature.
• During winter, the intensity of conventional Light sources tends to decrease. They need high voltage to illuminate in the winter. However, LEDs perform better in these circumstances. This is why they are used in the products like refrigerators, cold storage, freezers, and display cases. This remarkable feature makes it an ideal choice to apply in the outdoor campus and parking areas.
• The small adjustable size of the LED proves to be a positive point as it fits in almost every circuit. Originally, LEDs were used as indicators in the electric circuit. They can also be combined into a long series of lights, and they are used for decorative purposes.
• Flickering is observed when conventional bulbs are turned on since they require time to warm, whereas such conditions do not apply to the LEDs
• LED emits very little heat and Light released by the remain in the visible region; hence, many doctors have suggested using LED to treat Seasonal Affective Disorder.

Disadvantages of LED

LED has many advantages, but some disadvantages exist too. Some of them are:

• LED does not release white Light emitted directly. The colors are red, blue, and green. To get the white colors, primary colors, i.e., Red, Blue, and Green, are merged to produce white Light, and other techniques used are layering with the phosphorus that changes original light colors into white colors.
• The Light produced by the LED is directional, i.e., they are emitted in one direction. Other light sources, particularly incandescent lights, can produce Light in every direction. Therefore, it sets the conditions for special lights to be used.
• LEDs do not possess filament that could be damaged, but LED has a problem with lumen depreciation. In this problem, the LEDs' original output reduces over time.

The quality of Light produced by the LED depends on the outside temperature. High temperatures may damage several parameters of the LED.