sentences:  It has a great potential as a green down-conversion phosphor for white LEDs; a yellow variant also exists (α-SiAlON).For white LEDs, a blue LED is used with a yellow phosphor, or with a green and yellow SiAlON phosphor and a red CaAlSiN3-based (CASN) phosphor.White LEDs can also be made by coating near-ultraviolet(NUV)-emitting LEDs with a mixture of high-efficiency europium-based red- and blue-emitting phosphors plus green-emitting copper- and aluminium-doped zinc sulfide (ZnS