Last October, the biologist and former GE Healthcare chief scientist James Rothman received the Nobel Prize in Physiology and Medicine for solving the mystery of how cells shuttle molecules of insulin and other substances to the right place in the body. This year, two other former GE scientists looking for new sources of light, Bob Hall and Nick Holonyak Jr., almost felt the glow of a Nobel themselves.
The Nobel Committee awarded the 2014 Nobel Prize in Physics to a trio of scientists, two Japanese and one American, for inventing in the 1990s “efficient blue light-emitting diodes [LEDs], which has enabled a bright, energy-saving white light source.”
The blue LED had been the lighting industry’s Holy Grail for three decades, ever since Hall invented the semiconductor diode laser in 1962, and Holonyak quickly followed with the first practical LED emitting visible red light later that year. (Russia’s Oleg Losev, who worked in St. Petersburg in the 1920s, has been recognized as the inventor of the first glowing diode.)
Hall, 95, and Holonyak, 85, were working in GE labs in upstate New York when Hall developed a precursor of the modern LED, the world’s first semiconductor laser. Today, diode lasers based on his research are everywhere, from grocery store checkout scanners and TV remotes to DVD players.
But Hall’s laser diode only emitted invisible infrared light. “Bob beat me to the first laser out of a semiconductor, but you needed a snooperscope to see the light,” Holonyak says, referring to a type of night vision telescope. He kept tinkering with his semiconducting crystals and made them emit visible red light a few months after Hall’s breakthrough. “Nobody could get the photons out of the semiconductor crystals,” he says. “But we used a process called stimulated emission to get them out. We knew that in 1962, and Bob is the next person I would have given the Nobel Prize.”
Hall retired from GE and Holonyak left the company in 1963, shortly after his discovery. He started teaching electrical engineering at the University of Illinois, where he remains today as professor emeritus.
