History of LED
1907
Henry Joseph Round first observed the phenomenon of electroluminescence in a piece of Silicon Carbide (SiC)
1920
Bernhard Gudden and Robert Wichard Pohl carried out further experiments using phosphor material made from Zinc Sulphide doped with Copper.
1936
George Destriau published a report on the emission of light by Zinc Sulphide (ZnS) powders, following the application of an electric current. He was credited with inventing “electroluminescence”.
1950's
1960's
The visible (red) light LEDs were produced using Gallium Arsenside Phosphide.
1970's
By the mid 1970’s Gallium Phosphide was itself being used as the light emitter and was soon producing a pale green light.
1980's
The use of Gallium Aluminium Arsenide Phosphide LEDs brought the first generation of superbright LEds, first red, then yellow and finally green.
1990's
The first significant blue LEDs also appeared using Silicon Carbide.
2000's