Near UV and blue-based LED fabricated with Ca 8Zn(SiO 4) 4Cl 2:Eu 2+ as green-emitting phosphor

Abstract

Green-emitting phosphor Ca 8Zn(SiO 4) 4Cl 2:Eu 2+ has been prepared by the solid state reaction method and there luminescence properties are investigated. The excitation spectrum of Ca 8Zn(SiO 4) 4Cl 2:Eu 2+ shows an intense excitation band in the blue centered at 450 nm and emits with a maximum at 505 nm. The concentration quenching mechanism is studied and verified to be the energy transfer among the nearest-neighbor ions. Upon 450 nm excitation, the emission intensity of Ca 8Zn(SiO 4) 4Cl 2:Eu 2+ is much stronger than the green emitting Ca 3SO 4Cl 2:Eu 2+ phosphor and even higher than YAG:Ce 3+. This excitation spectrum range matches UV and blue light-emitting diodes (LEDS) chips very well, suggesting Ca 8Zn(SiO 4) 4Cl 2:Eu 2+ could be a promising green emitting phosphor candidate for LED devices.