Luminescence properties of Ca2 Ga2 SiO7 :RE phosphors for UV white-light-emitting diodes

A series of Eu(2+) -, Ce(3+) -, and Tb(3+) -doped Ca2 Ga2 SiO7 phosphors is synthesized by using a high-temperature solid-state reaction. The powder X-ray diffraction and structure refinement data indicate that our prepared phosphors are single phased and the phosphor crystalizes in a tetrahedral system with the ${P\bar 42m}$ (113) space group. The Eu(2+) - and Ce(3+) -doped phosphors both have broad excitation bands, which match well with the UV light-emitting diodes chips. Under irradiation of λ=350 nm, Ca2 Ga2 SiO7 :Eu(2+) and Ca2 Ga2 SiO7 :Ce(3+) , Li(+) have green and blue emissions, respectively. Luminescence of Ca2 Ga2 SiO7 :Tb(3+) , Li(+) phosphor varies with the different Tb(3+) contents. The thermal stability and energy-migration mechanism of Ca2 Ga2 SiO7 :Eu(2+) are also studied. The investigation results indicate that the prepared Ca2 Ga2 SiO7 :Eu(2+) and Ca2 Ga2 SiO7 :Ce(3+) , Li(+) samples show potential as green and blue phosphors, respectively, for UV-excited white-light-emitting diodes.