Electronics IQ Challenge

LED Lighting History

LEDs We all know that LED stands for Light Emitting Diode, but some may not know that the invention of the LED goes back to the discovery of electroluminescence in 1907 when British experimenter H. J. Round of the Marconi Labs used a crystal of silicon carbide plus a cat's whisker. (A cat's whisker detector is an antique electronic component consisting of a thin wire that lightly touches a crystal of semiconducting mineral to make a crude contact-junction rectifier.)

True LED lighting would have to wait until the early 60s when Texas Instruments, General Electric and RCA Laboratories all played a role in developing the technology. Miniature crystals (gallium arsenide) would emit infrared radiation when electric current was applied and that became the first (infrared) LED.

The first visible spectrum LEDs were colored red and today we enjoy a full palette of colors.

A Walk through LED Lighting History

1907 - Light Emitting Solid
1955 - Infrared LED
1962 - Red LED
1971 - Blue LED
1972 - Yellow LED
1972 - Amber LED
1995 - White LED
Late 1990s - UV LED