Imagine a light that almost never burns out, is indestructible, and converts way more electricity into light than its predecessors. Pack it all into a tiny amount of space and you might well be wondering if we are talking about a magic lamp. What we are imagining, however, is a light emitting diode (LED).
The problem with incandescent lamps, which are still used largely, is that they aren’t energy efficient. The process of igniting a filament housed in vacuum to create light uses only about 10% of energy available as light, losing the rest as heat. The LEDs that are in use today are way more efficient when compared to these. Nick Holonyak, Jr. is the man behind these LEDs.
Bardeen’s doctoral student
The son of immigrants from what is now western Ukraine, Holonyak enrolled to study electrical engineering from the University of Illinois and received his Bachelors (1950), M.S. (1951) and Ph.D. (1954) degrees. Having taken a course in atomic physics with John Bardeen, Holonyak became his first doctoral student in 1951. As the co-inventor of transistor and discoverer of BCS theory (a fundamental theory of conventional superconductivity), Bardeen went on to become the only person to win the Nobel Prize in Physics twice (1956 and 1972).
Following his Ph.D., Holonyak spent a year with Bell Laboratories and two years with the military, before eventually joining GE’s research facility. During this time, engineers and scientists at GE were researching semiconductor applications and building the forerunners of modern diodes.
GE scientist Robert N. Hall achieved success in building a semiconductor laser. Hall’s laser, however, only emitted invisible, infrared rays. Holonyak aimed for the visible and he believed that “if they can make a laser, I can make a better laser than any of them”.
An alloy does the trick
Holonyak had an alloy of gallium arsenide phosphide (GaAsP), which he believed would help him. Others were open in their disagreement with Holonyak’s hypothesis but he, nevertheless, went ahead with his work.
Holonyak spent hours in his labs, cutting, polishing and testing his hand-made semiconductor alloys. And on October 9, 1962, Holonyak presented the first visible LED to his GE colleagues who were looking on. Some called it “the magic one” and Holonyak believed that the red light emitted by his mixture was only the beginning.
Works with his students
Holonyak left GE in 1963 and went to teach at his alma mater, the University of Illinois. He set up a laboratory with a small group of students studying electrical engineering and physics. His expectations were high and he motivated his students by saying that they had to beat larger teams with better funding in other labs.
His hopes paid off as one of his students, George Craford, went on to create the first yellow LED in 1972 and also increased their brightness by ten times. By 1977, Holonyak’s team also demonstrated the first quantum well lasers, the likes of which are found in CD and DVD players. Green and blue lights were first developed in the years that followed, before eventually white LED light came about.
When Holonyak first produced LED light, he knew he was onto something powerful and expected that these materials would eventually replace incandescent lamps in a decade or so. It’s been over half a century now, but the process is still ongoing. The days are surely numbered for incandescent lamps as LEDs continue to directly replace them.
