White light-emitting diodes of GaN-based Sr₂SiO₄:Eu and the luminescent properties

We have synthesized a Eu²⁺-activated Sr₂SiO₄ yellow phosphor and investigated an attempt to develop white light-emitting diodes (LEDs) by combining it with a GaN blue LED chip. Two distinct emission bands from the GaN-based LED and the Sr₂SiO₄:Eu phosphor are clearly observed at 400 nm and at around 550 nm, respectively. These two emission bands combine to give a spectrum that appears white to the naked eye. Our results showed that GaN (400-nm chip)-based Sr₂SiO₄:Eu exhibits a better luminous efficiency than that of the industrially available product InGaN (460-nm chip)-based YAG:Ce. © 2003 American Institute of Physics.