How did LED lights come into Existence?

What is LED?

LED or Light Emitting Diode is right now the most famous, energy-efficient, and reliable source for lighting systems. LED is basically a semiconductor that produces light when some electricity passes through it. It works on the concept of Electroluminescence. LEDs don’t need heat for the production of light unlike other light sources such as halogen, CFLs, or incandescent bulbs. Its size is comparatively very small which is around 5 mm of the diode. Hence in an LED light lamp, there are multiple LEDs placed on it according to the requirements. LEDs were developed slow-paced but now these are the most efficient light source as huge development has been done on it.

First Discovery

As we discussed, this device works on the principle of electroluminescence. The first discovery was made on this phenomenon in 1907 by an English scientist named H.J. ROUND while working in MARCONI LABS. Electroluminescence is a phenomenon in which material emits lights when some electric current passes through them. His experiment was made using silicon carbide crystal. He observed that when electricity passes through it, it emits yellow light. Therefore the yellow light LEDs were the first made LEDs and because of it, we saw yellow lights in old fiction movies. But yellow light alone could not resolve our issues. That is why we needed many experiments and advancements.

Experiments

1927-

The first experiment was made by Russian Scientist Oleg Vladimirovich Losev in 1927. He distributed his research in different journals but no practical use was made on its discoveries.

1936-

After the discovery of 1937, there were no advancements made for a decade.  But in 1936 a scientist named Georges Destriau observed that when some electric current is applied to zinc sulfide suspended in an insulator, it can produce light. So this year, he discovered a new material (zinc sulfide powder) to produce light.

1936 - 1961

Many small discoveries were made by many scientists and experimenters during this time period.

1961

This year, an experiment was made accidentally by Robert Biard, James, Dallas, Texas, and Gary Pittman while working in Texas Instruments. They discovered that they have made an LED that emits infrared light. Initially, this was of no use because infrared lights are invisible to the human eye but now we use them for our remote controls.

1962

The first Street lights for practical use were invented in 1962 by Nick Holonyak and Jr. Their observations made it possible for LEDs to emit red light. He used Gallium Arsenide for this experiment. Again, only red light is not enough for our use as we need a white light to see objects. To make white light we need to complete the RGB spectrum i.e. when these three colors, red, green, and blue mixed together, they produce white light. Now till here, we have red light but the other two colors are missing.

1990≈

In the early 1990s, scientists produced lights of green and yellow colors. These lights were produced by experimenting with semiconductor material Indium Gallium Aluminium Phosphide. Now scientists have invented green and red light. The missing part of the spectrum is blue light. However, the invention of blue light was a whole new challenge for scientists but here we will discuss it shortly.

1994

The Last Missing Part of Spectrum... In 1994 a legendary scientist named Shuji Nakamura finally invented blue light using Gallium Nitride. These blue lights completed the spectrum and then we finally reached a new era of lighting systems. Because of his invention, Shuji Nakamura got huge fame.

And at last, we got white bright LED lights. (Of Course by experimenting and combining all three colors) 

crestled