The blue LED was supposed to be impossible—until a young engineer proposed a moonshot idea.
The first blue LED I ever saw was on the dashboard of my mom’s VW Golf. I always wanted one like that, but now they’re everywhere!
My favorite thing about widely-available blue LEDs was the effect on TV scifi.
Watch the Star Trek shows made in the 1980s and 1990s and the tricorders, alien gadgets, and other props were always twinkling with red, yellow, and green LEDs to look futuristic. A generation later and every single hand prop on 2000s Doctor Who, Torchwood, etc. glowed and twinkled blue because the LEDs had just become cheap enough for prop makers, but weren’t yet widespread in day-to-day life so the viewers were seeing something strange and unusual.
Now every color of LED imaginable is just common and whatever, but for a good stretch of time glowy blue became the standard “scifi” color just because that particular tech happened to turn up at that particular time.
Really annoying that the company shat on him for years, and continued to do so after he multiplied the value of the company. Toxic behavior.
It’s an extreme example that perfectly illustrates how profit is extracted from employees by the employers. He didn’t have any leverage to get a larger share of the profit from his labor, as is the case with most employees. You could call it toxic behavior, and it is, but it’s the expected behavior, the behavior incentivised by the system.
This was an yet another glorious episode from veritasium.
I hope we get well past UVC LEDs. (i.e., shorter wavelengths) UV LEDs are already available. Unfortunately, this progress will stop before X-ray light. With +1 KeV energy, you pretty much must blast off the electrons from the atoms to emit X-rays, which an x-ray tube already does. Or by peeling off a piece of scotch tape.
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Light = energy, shorter wavelengths= higher energy. Blue light has a shorter wavelength than red light. UV has even more energy. X-Rays have a lot more energy. For reference in the visible spectrum were talking about maybe 1-4 eV (this may be wrong, I’m too drunk to look it up rn).
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If we want to produce light, the aim is to find an energy gap that has the exact energy gap that corresponds to the wavelength we’re interested in. Typically this corresponds to an electronic transition, i.e. an electron “jumps” into a higher orbital, on its way down it will emit the energy difference as light.
2.1 X-Rays rn are produced by accelerating electrons onto a metal plate with high voltage. The impact of the electron “rips” out an electron in the close vicinity of the nucleus. Another electron will take the place of that electron, the energy gap associated with that process is large, which is why it produces X-Rays.
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If we want to produce LEDs that emit in the far UV range we have to find large energy gaps in materials which is difficult. We still have to have a way to get the electron across the energy gap using electricity.
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X-Ray LEDs are probably not realistic, as the energy of x-rays is so large that we have to rip out electrons from the close vicinity of the nucleus… which is already what we’re doing with X-ray tubes.
Shuji Nakamura was a researcher at Nichia who was determined to create the first blue LED, which had eluded scientists for decades. Through innovative crystal growth techniques and materials discoveries, he succeeded in developing bright blue and white LEDs in the early 1990s. This breakthrough enabled LEDs to be used for full-spectrum lighting. Nichia’s fortunes grew enormously as a result, though Nakamura was not properly compensated for his invention. Today, LEDs powered by Nakamura’s blue LED technology are ubiquitous and have brought enormous energy savings worldwide.
Something interesting I found was that Nakamura persisted in his research for blue LEDs against the wishes of his company management, who saw it as a waste of resources. His stubbornness and belief in his work paid off by solving a problem that had stumped the electronics industry for 30 years.
