LED - explanation and definition of LED

What is a LED

LED is an electronic component whose function is to convert electrical energy into a light source, the word comes from the acronym Light Emmiting Diode.

Specifically a LED corresponds to a particular type of diode which converts electrical energy into light, its operating principle is based on the emission of photons (light) when the carrier electrons of electricity pass through the diode, this phenomenon is called electroluminescence.

Although the principle is the same, electroluminescence, we have to differentiate LEDs, from the OLEDs, the latter incorporating organic compounds in its structure and even polymers, while the first are composed solely of inorganic semiconductor compounds.

Today LEDs experiencing a boom in the use of different applications, from its application in simple remote controls to use in making huge television screens, LEDs have experienced a long road of research and study since the beginning of the XX century to this day.

The first discoveries about the technology behind the operation of Led, electroluminescence, are attributed to the English Henry Joseph Round when he discovered the light effect that occurs when electrical current passing through certain semiconductors, their discoveries were sent to the prestigious Electrical World magazine in 1907.

Later in 1927 the Russian physicist and engineer Oleg Rsev made the first written report on the lighting effect that occurs when electrical current passing through semiconductors (diodes) used in radio communications, manufacturing the first LED in history with zinc oxide and silicon carbide.

In 1961 scientists Bob Biard and Gary Pittman discovered by accident the first LED of infrared light, but it was not until 1962 when it was developed the first LED visible light discovered by the American scientist Nick Holonyack, in the same year he launched the market the first red LED at a price of $ 130 each (today the price of a similar led misses 10 cents), 10 years after the first green, yellow and orange LEDs were launched. Given the low luminosity that its application was aimed at getting signaling electronics, IBM being the first company to introduce its electronics.

In the 90s the first white light LED with high brightness were developed, opening up a wide range of possibilities in the lighting industry.

Advantages and disadvantages of LEDs

As with any type of material and technology, the LEDs have a number of advantages and disadvantages, knowledge of which allow us to know their advantages and limitations in various applications where we want them.

The main advantages of LEDs are:

• Low energy consumption being more efficient than traditional incandescent and fluorescent lamps, since they emit more light per watt consumed.

• They can be manufactured with a very small size, allowing to insert and assembly into electronic circuits and devices reduced in size.

• They are very resistant to vibration and impact, having a high rate of reliability and durability, having a half-life 50 times higher than incandescent lights.

• Has on and off times of less than 1 millisecond, not by lowering his life and durability by the intermittent lighting.

The main disadvantages of the LEDs are:

• Its main disadvantage is its high dependence on temperature, decreasing the brightness and lifetime with increasing temperature and heat to which they are exposed, having reliability problems when exposed to sudden temperature changes.

• Being a relatively new technology the initial acquisition cost is higher compared to traditional incandescent and fluorescent sources, but their savings is determined by its low consumption and its long life.

Applications of LEDs

Due to its high efficiency and durability as well as its small size LEDs are experiencing a fast expansion in different areas and industrial applications, undoubtedly LEDs are part of our everyday lives.

The first sector to use LEDs was the electronics sector, due to its small size, low power consumption and fast on and off times, LEDs are ideal candidates for light signaling state on, off or other information in a small appliances such as electronic boards, calculators, displays...

The invisible or infrared LEDs are used to send information between different electronic devices, remote controls from television, garage doors or our air conditioning are examples where infrared LEDs are used, on the other hand at the beginning of XXI century were widely used in communication between computers and cell phones, currently being replaced by the bluetooth technology.

With the development in the 90s of the luminescent leds these are being applied successfully in various areas of lighting, today we have lamps that illuminate our streets through this kind of LEDs, thousands of shop windows, museums, houses and even industries worldwide are illuminated with LEDs, including flash that illuminates the camera of your cell phone or Smartphone is LED.

Traffic signals, headlights of cars and locomotives, traffic signal displays, informational displays, giant television screens used in sports, music or other events, are examples where the LEDs is the basic element of its manufacture and operation.