Nanotech makes white LEDs 5x brighter than before with warmer light. Answered
New research with nanocrystals has created a new LED that gets 300 lumens per watt. Even better, the light is a warm white and not the cold blue-tinted white that we all know.
The crystals absorb some of the LED's blue output and emit their own red and green light. That combines with the remaining blue light to produce a soft white glow.
Existing commercial white LEDs are also based on blue LEDs. But they use a phosphor coating that converts some blue light into a broad spectrum of yellow light. When mixed with remaining blue light the result is a harsh blue-hued white.