>>8776823It's not just a matter of improving existing tech, to get a native white diode you need a metal that glows pure white without melting. I don't know the physics so I don't know if that's even possible the way they do it, since white is a combination of wavelengths and not a single position on the spectrum.
Also then you have to figure out the manufacturing process for it. Blue lasers took a while because even after the Japanese inventor found the right metal, it had such a high melting point that the convection currents would fuck up the existing way of making a goddamn diode with it. He solved it by adding a second spray nozzle to the chamber to counteract the currents (and then made a shitton of money from patenting the only blue LED/laser at the time)