I just installed 3 of the new color bulbs in a craft room. While playing with the settings, I discovered that if you set the color to pure blue, items that normally react to ultraviolet light glow brightly. For example, para-cord and paper labels that are made with high-viz paint shine very brightly in orange and green. There is still a lot of visible blue light, of course, so this is not like a regular ultraviolet lamp.
I suspect that UV was added to the LEDs to make colors pop.
Well it’s called ultraviolet for a reason. After blue, indigo, and regular violet. It’s the same spectrum. Nothing added.
It’s a natural byproduct of the phosphors used to generate the blue.
LED uses phosphors? I thought that was only used in fluorescent.
"The first white LEDs, made without three individual LEDs, were made with the magic of phosphors. Phosphors are a well-understood science, most commonly found in lighting applications in fluorescent bulbs. Fluorescent bulbs don’t produce white light on their own, they produce ultraviolet light by exciting mercury vapor. However, by coating the inside of a fluorescent bulb with a powder, this ultraviolet light can be converted into red, green, and blue light. The result is a fluorescent bulb that lights your garage or workshop.
This can be done with LEDs as well. With an ultraviolet or violet LED packaged inside a phosphor-coated enclosure, you can make a white LED. This is known as a full-conversion white LED."
No, blue is made by exciting electrons and letting them fall back into their valance shell and emitting a photon.
“The puzzle behind making a high-brightness blue LED was first cracked in 1994 at the Nichia Corporation using indium gallium nitride. At the same time, Isamu Akasaki and Hiroshi Amano at Nagoya University developed a gallium nitride substrate for LEDs, for which they won the 2014 Nobel Prize in Physics. With red, green, and blue LEDs, the only thing stopping anyone from building a white LED was putting all these colors in the same package.”