While it's true that the history of LED lights isn't long in comparison to incandescent lights or Edison bulbs, the technology has been around longer than you might think. Most folks assume that LED lights are relatively new, mainly because they've only become easily accessible in the last decade or so. Learning about their history, such as who invented LED lighting and how it came to be, will make you appreciate the bulbs for their innovation as well as their energy efficiency and their ability to save money on your power bill. You'll find yourself thinking about the engineers and scientists behind the invention every time you screw in a light bulb.
A Brief Explanation of LED
To fully understand the history of LED lights, you first have to know what they are. LED stands for light-emitting diode. LED lights are electric components. They give off light only once they connect to a direct current. Following the electroluminescent principle, LED can emit visible light, along with infrared lights and ultraviolet. LEDs are characterized by a low energy burn, their lengthy lifespan, their ability to switch swiftly, and their size, which is smaller than traditional bulbs.
It took a while to work out the science and technology behind LED lights, however. Today, you can find LEDs at any store. Many of them come as part of a smart lighting kit that people can control from their cell phones or the hub they install at home. That variety comes after a hard-won battle and an interesting history.
The Silicon Carbide Connection
Technically speaking, Henry Joseph Round is the person who invented LED first, all the way back in 1907. Round was a British scientist who worked in the Marconi labs. He applied 10 volts to carborundum crystal. In other words, he created a current using silicon carbide—and it worked.
Unfortunately, the pale yellow light that resulted from his experiments didn't amount to much. It certainly wasn't enough to light up a room, or even a lab. Because the test seemed like a dud, no one bothered to touch the research for decades.
Twenty Years Later
By all accounts, no one bothered much with the concept of light-emitting diodes for the next two decades, until 1927. At that point, Russian scientist Oleg Vladimirovich Losev proposed a theory that relied on Henry Joseph Round's findings. Losev titled his paper, “Luminous carborundum detector and detection effect and oscillations with crystals,” making it appear that he was right on the precipice of cracking the LED code. Nothing much came from his paper, however, and yet again, the history of LED lights stalled for a few more decades.
Coming Up On Infrared
It took until 1955 for additional research to take place on the subject. That year, an employee at Radio Corporation of America, Rubin Braunstein, discovered a few of the secrets behind infrared light. Specifically, he revealed that some, but not all, simple diodes can put forth infrared when they have an active connection to a current. In spite of Braunstein's renown as a physicist, however, LED experiments once more stalled—but not quite as long this time.
Texas Instruments to the Rescue
Analysis resumed six years later, in 1961, courtesy of Bob Biard and Gary Pittman, engineers and inventors who worked at Texas Instruments. Through their work, they uncovered the fact that gallium-arsenide diodes also give off infrared as long as they have a stable current. They quickly made a smart move: they got the patent for infrared LED lights.
Biard and Pittman helped to speed along the technology significantly. It's only fair to name them as two of the men who invented LED lights, too. To do that, however, the world also has to give props to Nick Holonyak, Jr., an engineer who worked at General Electric. In 1962, he made a monumental discovery. As a result, he's responsible for the development of an LED that gave off visible illumination, i.e., it emitted a light that you could see on the visible spectrum of the frequency. It, too, was a red LED.
An Avalanche of Innovation
Holonyak opened up the floodgates, finally speeding up the history of LED lights, at least in terms of their creation. Holonyak's graduate student, M. George Craford, picked up where his mentor left off and went running with it. However, it took ten years to improve on Holonyak's research. Craford's investigation didn't take place until 1972, but it quickly proved to be worth the wait.
Not only did Craford develop a much brighter red LED light, but he was also the first engineer to perfect the emission of another color. He's responsible for coming up with the very first LED to emit visible yellow light. The technology still wasn't complete, but Craford's discoveries ensured that other inventors and scientists could build on his efforts.
A Brighter Future
Come 1976, Thomas P. Pearsall stepped into the ring. His work resulted in the development of the brightest LED light yet. The high brightness LED he created came to be used alongside fiber optics technology, which led to extraordinary advances in telecommunications.
In 1979, the blue LED made its official debut. Shuji Nakamura, who worked for the Nichia Corporation, was the innovator behind its creation. From that point until 1994, however, LED lights proved to be too costly for commercial or residential use.
A History of Cost
In fact, the history of LED lights is mostly blank as it applies to residential use. It's funny that the most cost- and energy-efficient light available was too expensive to use for such a large part of its existence. LED lights were largely relegated to professional labs and, later, electronics.
In the beginning, you could expect to pay upwards of $200 per light, an exorbitant price no matter how much energy an LED light can save. At some point in the 1970s, Fairchild Semiconductors found a way to cut the cost of LED lights by changing their production processes. They began to use a planar method to make the semiconductor chips needed for light-emitting diodes. Their innovation is the only reason that LED lights don't still cost an arm and a leg today. Without it, we probably still wouldn't be able to afford them for commercial purposes.
As you can tell, it isn't as simple as listing a single person who invented LED lights. The truth is a bit more complicated than that and much more fascinating. You probably don't consider the history of LED lights as you swap out an old light bulb and screw in a new one, or as you pick out your first smart lighting kit at the store. Maybe now you can take a minute to appreciate the hard work and innovation behind the technology. You can also spare a second to browse the selection of LED lights at Atlanta Light Bulbs. Light up your corner of the world with a slice of history.