LED Light Bulbs: An Accidental Discovery?
Oct 9, 2020
Dernière mise à jour
October 9, 2020, 11:10:06 p.m.
How the quest to make a semiconductor laser led to better lighting that is more efficient, cost-effective and friendly to the environment.
Next to the sun, modern light-emitting diodes (LEDs) are one of the best sources of super-bright illuminating light.
But did you know that the first LED was invisible? Created by Robert Biard and Gary Pittman in 1961, this infra-red LED did not have any real practical use.
Not long after this discovery, the first visible LED was created in 1962. An interesting twist to the story, however, was that the scientist - Nick Holonyak Jr. - wasn’t trying to create a light bulb. His mission was to create a laser that was visible to the human eye.
Despite his accidental invention, Holonyak’s instincts led him to believe that these small yet efficient sources of light could replace incandescent bulbs. The first tiny LED bulb was finally created by M. George Craford - a student of Holonyak - while working at the Monsanto company.
LEDs have taken a remarkable journey since then, starting as little indicator lights on electrical equipment and circuit boards in the 1960s, and then morphing into lights on digital watches during the 1970s. They were then used as traffic lights in the 1980s and have been expanding ever since for use in massive spaces like warehouses and stadiums.
LED History: 1960s - Today
1961: Robert Biard and Gary Pittman invented the infra-red LED. Due to its invisibility, it did not have any practical use.
1962: Nick Holonyak, Jr. invented the first LED that produced visible red light while attempting to discover a laser. This earned him the title of “Father of the Light-Emitting Diode”.
1972: M. George Craford, a student of Holonyak, used green and red gallium phosphide chips to make an LED that produced pale yellow light that was much brighter than his mentor’s initial invention. This led his employer, the Monsanto Company, to mass-produce LED lights for public consumption.
Mid-1970s: Scientists improved LED technology to create LEDs that produced pure green light.
1980s: Further innovations resulted in the creation of first-generation super-bright red, yellow, and green LEDs that were used for traffic lights.
1990s: Ultra-bright blue LEDs were discovered by Shuji Nakamura, which then became the foundation for the cost-efficient and functional white LED lights used today.
And the rest is history!
LEDs today are six to seven times more efficient than the traditional incandescent bulbs, use 80% less energy and last 25 times longer than their incandescent counterparts.
Energy-efficient, bright and cost-effective, LEDs are now being used everywhere from the home to the office to industrial operations for a brighter, more environmentally-friendly future. Not bad for an accidental invention made almost 60 years ago!