This 30 minute video tells the truly extraordinary story of the development of the blue LED. It is a testament to the determination and perseverance of one man: Shuji Nakamura.

Highly recommended viewing:

https://www.youtube.com/watch?v=AF8d72mA41M

What an inspiration Shuji is. Shunned by Ph. D. know-alls, working under hostile management and almost continuous setbacks, he achieved
the "impossible".

It always makes my day when I hear multitude experts declare something "impossible".

That guy's videos, while entertaining, often leave a lot to be desired for accuracy.
Nichia's gallium nitride LEDs were the first >>affordable<< blue LEDs, but they certainly weren't the first. In 1987 Siemens introduced the first commercially available mass-produced blue LEDs, made using silicon carbide. They were originally around $US100 each, but I bought some in 1991 for A$17, somewhat more reasonable. I used them for white balance indicators on video equipment used on film sets, where we needed such cool gimmicks to justify the enormous rental charges!
Before that you could actually buy gallium nitride LEDs from specialist suppliers, but they were even more insanely expensive, basically hand-made.
So Shuji Nakamura didn't actually invent the Gallium Nitride technology; he just found a way to make it manufacturable.
It was known since the early 20th century that silicon carbide crystals could be made to emit a blue glow in a strong electric field, so it was not an entirely unexpected development. It's also not generally known that OLEDs were first made in the early 1960s, around the same time as the first red LEDs.

Shuji Nakamura didn't actually invent the Gallium Nitride technology; he just found a way to make it manufacturable.

Yes, and I thought that was shown quite well in the documentary.

"I bought some in 1991 for A$17, somewhat more reasonable"

Do you still have one or two kicking around?

"Do you still have one or two kicking around?"

Somewhere I do. Once, for a TV commerical I made a pair of "Terminator" type sunglasses with 2.5mm Silicon Carbide Blue LEDs to give pinpoint blue eyes. I bought a cheap pair of "wraparound" sunglasses, filed the tops of the LEDs flat, stuck them to the insides of the lenses with super glue, and then put on dabs of black paint so the actor could see (more or less). They looked pretty stunning at the time because nobody had ever seen anything like that before.
I saw the glasses a while back while cleaning up my garage, but I'm not sure what I did with them. They're different to Silicon Nitride LEDs, having a colour more in the cyan direction and a 4.5 Volt conduction voltage.