As far as I understand, you need to be able to mix red, green and blue light to get white light and replace lightbulbs. But the earliest example I can find of white LEDs used a blue LED and a yellow (apparently the result of mixing red and green light) phosphor coating to scatter the light across the visible spectrum. Why couldn’t something similar be done with a red LED and a cyan (mixing blue and green) coating/cover to produce white light instead?
In: Engineering
There were plenty of “fake” blue LEDs before the real thing was invented. But they were too dim and inefficient to be useful, let alone light up a room.
LEDs are very efficient, yes, but if you need 10x the intensity to get usable light through a filtering material, heat becomes a huge issue. Super bright LED arrays used for some industrial applications need active cooling to not burn out, for example.
Latest Answers