Phosphor-free InGaN LEDs emit white light

Researchers at the King Abdullah University of Science and Technology (KAUST; Thuwal, Saudi Arabia) have invented a third type of white LED, which is monolithic, requires no phosphor, and can be color-tuned to emit warm, natural, or cool white.

Fabricated via metalorganic vapor-phase epitaxy, the InGaN-based device contains both blue-light emitting quantum wells with a 20% indium content and 34% indium red quantum wells with a 34% indium content; to create broadband emission, the researchers created V-shaped pits in the structure below the quantum wells (which also had the effect of improving current injection). Combined, the monolithic LED emits light across the entire visible spectrum.