Phosphor-free white light-emitting diodes

The multiple color-matching schemes that could improve the color rendering index for phosphor-free white LEDs are discussed.Then we review a few of the recent research directions for phosphor-free white LEDs,which include the development of monolithic GaN-based white LEDs and hybrid integrated GaN-based and Al Ga In P-based white LEDs.These development paths will pave the way toward commercial application of phosphor-free white LEDs in the coming years.