The Big Impact of Tiny LEDs: An Innovator's Journey
In this day and age, it is virtually impossible to go an entire 24 hours without seeing an LED.
Light-emitting diodes (LEDs) are everywhere. They light up cell phones, the ball that drops on New Year’s Eve in Times Square and modern flat-screen TVs .
One man is credited almost entirely with the development of the technology behind all of these ubiquitous devices. For his seminal work in the 1960s, Nick Holonyak has been honored at MIT as one of the most important innovators of the past half-century.
Let there be light
Before Holonyak, there was just one main way to produce electric light: incandescence. Conventional light bulbs, invented by Thomas Edison in 1879, create light when an electric current passes through a filament. Because of resistance to electric current, some energy escapes as light and heat. The greater the heat produced, the brighter the light.
Working for General Electric, Holonyak discovered a way to produce light through chemical reaction, not heat. The same process appears in nature — such as in the bodies of fireflies — but before 1962, scientists only managed to produce that kind of light by accident, Gilbert Held wrote in his book “Introduction to Light Emitting Diode Technology and Applications” (Taylor & Francis, 2009).
In that year, Holonyak discovered a way to synthesize an alloy that emitted light when charged with electricity, Held said. Tinkering with the alloy, Holonyak first produced a red hue, though Holonyak and his graduate students soon developed other colors.
A smaller, more efficient light bulb
The practical applications of LED quickly became apparent, as well as more widespread, as the technology improved.
First used as simple indicator lights in small appliances such as coffee machines, LED technology now illuminates large billboards, including the NASDAQ sign in New York, according to the University of Illinois.
Perhaps most significantly, LEDs are being considered “as replacements for fluorescent bulbs, which, in turn, had been developed as replacements for energy-inefficient incandescent light bulbs ,” wrote Held.
In addition to their usefulness in everyday life, LED lights also offer a distinct economic advantage, with a life span more than ten times longer than that of the average incandescent bulb, according to the University of Illinois.
LED technology wasn't Holonyak’s only contribution to the scientific world. He also invented the household dimmer switch and the red laser technology used in reading CD and DVDs, according to the National Inventors Hall of Fame profile on the scientist.