Standing on Edison’s Shoulders: 50 Years Ago, the World’s First Practical LED Turned On
|Red light radiating from the world’s first practical LED|
That “lamp of the future,” of course, is what we now call the light-emitting diode, or LED. Manchester could make his prophesy because he interviewed GE physicist Nick Holonyak who, in 1962 — 50 years ago this fall — built the world’s first LED. Holonyak’s diode emitted only red light, but it lit a research boom whose multi-colored offspring now illuminate homes and cities, the latest iPad “retina” screens, and flat-screen TVs. “Boy, those were the golden years,” says Holonyak, now 83 years old. “When I went in, I didn’t realize all that we were going to do.”
Holonyak, whose parents immigrated from what is now western Ukraine, enrolled to study electrical engineering at the University of Illinois. He took a course in atomic physics with John Bardeen and, in 1951, became Bardeen’s first doctoral student in his new semiconductor laboratory. “This is where everything started,” Holonyak says.
Semiconductors, of course, are the lifeblood of modern electronics. They power everything from toys to Mars landers. In 1956, just five years later, Bardeen shared the Nobel Prize in Physics with William Shockley and Walter Brattain for building the first semiconducting transistor. Bradeen won another Nobel in 1972.
Holonyak got his PhD in 1954. In 1957, after a year at Bell Labs and a two-year stint in the Army, he joined GE’s research lab in Syracuse, NY. GE was already exploring semiconductor applications and building the forerunners of modern diodes, called thyristors and rectifiers. At a GE lab in Schenectady, the scientist Robert Hall was trying to build the first diode laser. Hall, Holonyak and others noticed that semiconductors emit radiation, including visible light, when electricity flows through them. Holonyak and Hall were trying to “turn them on,” and channel, focus and multiply the light.
Hall was the first to succeed. He built the world’s first semiconductor laser. Without it, there would be no CD and DVD players today. “Nobody knew how to turn the semiconductor into the laser,” Holonyak says. “We arrived at the answer before anyone else.”
But Hall’s laser emitted only invisible, infrared light. Holonyak spent more time in his lab, testing, cutting and polishing his hand-made semiconducting alloys. In the fall of 1962, he got first light. “People thought that alloys were rough and turgid and lumpy,” he says. “We knew damn well what happened and that we had a very powerful way of converting electrical current directly into light. We had the ultimate lamp.”
Holonyak left GE in 1963 and started teaching at his alma mater, the University of Illinois. Today, he is the John Bardeen professor of electrical and computer engineering and physics. He’s collected dozens of top prizes for his work, including the National Medal of Technology and Innovation, the Lemelson-MIT Prize, and membership in the National Inventors Hall of Fame.
The red LED “was just the beginning,” he says. “I knew that it was a very powerful thing and that these materials will become a source of white light. I thought it might be a decade. Little did I realize that it would take much longer than that.”