LED: Light Emitting Diode
LED stands for light-emitting diode. It is a semiconductor light source which emits light when applied a predetermined voltage.
This is a PNJunction Diode that emits light when a voltage higher than the threshold voltage is applied.
Because of its excellent quality, LEDs are used in many electronic devices today.
LED is the newest invention and is used daily by most people.
Construction of LED
The LED is created by combining P and N-type semiconductor material.
We all know that silicon and germanium can be used in normal semiconductor diodes, but not in light-emitting diodes.
Gallium arsenide (GaAs), or gallium arsenidephosphate (GaAsP), can be used in its place.
Because of its unique characteristics, this material is often used in LED. This material emits light and not heat when applied voltage.
LED is used as a forward bias device.
Principle and operation of LED
LED is based on Electroluminescence.
Electroluminescence is the property of semiconductor material that converts electrical energy to Light Energy.
As mentioned earlier, LED is a Forward Bias semiconductor devices. This means that it will begin to work when the p terminal will be connected to a positive potential of a lithium battery and the N terminal to the negative terminal.
So the negative voltage applied to the battery causes the holes on the P side to repel, while the negative voltage caused by the Battery’s positive voltage acts as a magnet for the electrons on the N side.
This repulsion causes electrons to move from the Valance band to the conduction band.
Electrons release energy during their movement, but a LED emits light energy because of its material.
Different colors of LED
LEDs are available in many colours today, so we can choose LED based on our requirements.
You’d be surprised to learn that the original LED was red. Over time, other colours were added.
The hardest part was getting the white LED colour. This was only possible a few years ago.
Then LED was popularized for in-home lighting.
Uses for LED
LEDs are being used in many areas today, with some notable examples.
- Tv backlighting
- Backlighting for smartphones
- Display of leds
- Automotive lighting
- Dimming light
- LED wallpaper
- Home lightning
- Decoration for the home
Benefits of LED
LED offers many benefits over traditional light. Here are some of its major advantages.
The most efficient light source of all is the LED.
The old bulb can give you an idea of how efficient the LED is. A 9-watt LED produces more light than a 100W bulb.
LEDs are so energy-efficient that 303 lumens can be achieved with just one watt of electricity.
LCD TVs can be replaced today by LED TVs because of their low energy consumption.
The LED light can be used long-term
This is another reason why LEDs are so popular and are used all over the world.
There are LED lights today that can last for over 100000 hours.
The LED is not as environmentally harmful as a CFL bulb. It does not contain mercury, lead, or Cadmium.
LED prices are very affordable today. Research is also decreasing the cost of LEDs every day.
A 9-watt LED bulb costs around Rs 50 today.
LED lights are easy to recycle and also cost less.
Compact size and light-weight
LED is light and compact, so it can be used anywhere.
Is LED powered by AC or DC current?
Only DC power is required for LED operation.
LED only works in forward bias. Therefore, it must only get current in one direction to function properly.
We convert AC current into DC in most electronic equipment that uses LEDs and then supply it to LED.
The LED will blink if AC current is supplied to it. This happens because AC current’s direction changes.
Other famous full-forms of LED-lighting are also available.
LED- Low Energy Use (in Academics).
LED-Low Energy Detector (in administration)
LED-Laptop Entry Disk (in computers, and computing)