LED history and its further development has taken place in parallel to the 20th century. In 1907, Henry Joseph Round, a specialist in radio communications, discovered the physical effect of electroluminescence. For many years, the finding went unnoticed by the scientific community.
First LED was designed by Oleg Vladimirovich Losev (who made a LED with zinc oxide and silicon carbide). Losev published details of his work in 1927, in a Russian scientific paper, opening the way for later discoveries.
Considered the father of modern LED, Nick Holonyak invented the first LED emitting in the visible spectrum in 1962, while working for General Electric. Fifteen years later, as a professor at the University of Illinois, he discovered the quantum-well laser, which opened the doors to the communication through fiber optics, CD players and numerous applications in medicine.
Regarding the industrial LED application, it was in the 60’s and 70’s when it had a great development. In 1962, in parallel to Holonyak discover, it goes on sale the first red LED. It served as an indicator, because its light was still not enough to illuminate a large area. It is not until 1971 that are available other LED colors: green, orange and yellow.
In the 90's, developes the ultraviolet and blue, allowing LED to create white light by luminescent conversion in 1995. This fact and the high brightness achieved makes it a very useful element in illumination.
LED has been and is still in continuous development. For over thirty years, has been used as industrial lighting and signage, consumer products such as smart phones, televisions, cars, computers, traffic lights or in the field of decoration. Its efficiency is improved rapidly and already exceeds 100 lm / W.
