Visible LEDs Celebrate Their 50th Birthday
Lee Rannals for redOrbit.com – Your Universe Online
One technology has only just begun to be implemented into our society on a wide-scale, but it has actually been around for 50 years: the LED.
Holonyak had predicted that the LED would replace incandescent lights, but at the time he probably didn’t realize it would take 50 years to gain some traction.
The scientists at GE Advanced Semiconductor Laboratory were researching a way to create energy-efficient visible light from LEDs.
Before 1962, the only light emitted from LEDs was infrared, so researchers were trying to produce a visible LED.
Holonyak used a mixture of gallium arsenide and gallium phosphide (GaAs phosphide) to make LEDs work on the visible light spectrum.
After showing off his feat to GE executives, Holonyak predicted in the February 1963 issue of Reader’s Digest that the LED would eventually replace incandescent bulbs.
While the first visible LED light was red, it took 10 more years for Dr. M. George Craford to create the first yellow LED in 1972.
Back in 1968, producing visible and infrared LEDs could cost $200 per unit, making the idea of using the lighting system instead of incandescent bulbs seem impractical. However, with the prices of the lights going down, and governmental regulations on incandescent bulbs increasing, it took 50 years for Holonyak to see his 1963 prediction finally start coming to fruition.
Now, LED light bulbs are being sold in stores to be used in place of incandescent. Many cities have even started to replace their street lamps with the 50-year-old technology.
Christmas lights have begun to conform to the technology and TVs have started to adapt, as well. LEDs are proving to be more energy efficient and more cost effective over the long run. They last longer than incandescent light bulbs and they consume far less energy in use.
Holonyak created something 50 years ago that was ahead of its time. Now, time has finally caught up with it and the visible LED bulbs are finding their place in the modern world.