Near UV and blue-based LED fabricated with Ca8Zn(SiO4)4Cl2:Eu2+ as green-emitting phosphor

Green-emitting phosphor Ca8Zn(SiO4)4Cl2:Eu2+ has been prepared by the solid state reaction method and there luminescence properties are investigated. The excitation spectrum of Ca8Zn(SiO4)4Cl2:Eu2+ 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 Ca8Zn(SiO4)4Cl2:Eu2+ is much stronger than the green emitting Ca3SO4Cl2:Eu2+ phosphor and even higher than YAG:Ce3+. This excitation spectrum range matches UV and blue light-emitting diodes (LEDS) chips very well, suggesting Ca8Zn(SiO4)4Cl2:Eu2+ could be a promising green emitting phosphor candidate for LED devices.

► Intense green-emitting Ca8Zn(SiO4)4Cl2:Eu2+ has been prepared by solid state reactions.
► Their luminescence properties is investigated.
► The mechanism of concentration quenching of Eu2+ is studied in detail.
► The comparison of Ca8Zn(SiO4)4Cl2 with well known chlorosilicate phosphors in terms of PLE and PL spectra is made.
► The green LEDs are fabricated by coating the synthesized phosphors on a UV and blue LED chip.