The Synthesis And Luminescence Property Study Of Dicalcium Orthosilicate Phosphor Stabilized With P₂O₅at Ambient Temperature

White LEDs are called the fourth generation lighting for their higher luminousefficiency, lower power consumption, longer persistence，much more environmentfriendly and so on, compared with the incandescent or fluorescent lamps. One of themost important approach to fabricate white LEDs is the combination of nearultraviolet LED chips and ultraviolet-emitting triphosphor, so it has importantsignificance to develop novel ultraviolet-emitting triphosphor with high stability andefficiency. The silicate host phosphors have attracted many attentions of researchers,due to their wonderful chemical and thermal stability, as well as the low price ofhigh-purity silicate,.The dicalcium orthosilicate phosphors stabilized with P₂O₅were prepared withthe conventional solid reaction. The host materials with the chemical formula ofCa_2-x/2Si_1-xP_xO₄were determined by XRD and when x=0.12and0.29, they were foundto be α′Η-C₂S and α-C₂S phase respectively, which were high-temperature forms ofpure dicalcium silicate stabilized upon1000℃. The influence factors of thestabilization of α-C₂S phase with x=0.29were studied by substituting Eu²⁺, Ce³⁺andalkaline earth ions for Ca²⁺respectively.The α-C₂S phosphors emitted by Eu²⁺or Ce³⁺were reported for the first timehere. The obtained α-C₂S: Eu²⁺phosphors exhibited a strong green emission at513nm under the excitation of λex=372or413nm, and the effect of Eu²⁺concentrationon photoluminescence properties were studied in detail. The α-C₂S: Ce³⁺phosphorshowed broad excitation bands ranging from220⁴00nm and emitted blue emissionaround430nm.The α′-C₂S phosphors were successfully synthesized and their photoluminescentproperties were studied. It was found that for α′-C₂S: Eu²⁺phosphors, the emissionpeak lay at about495nm under the excitation of375and410nm. For α′-C₂S: Ce³⁺phosphors, the emission peak lay at about431nm and the excitation peak lies about 365and253nm. It’s clearly that the photoluminescence properties are effectivelyaffected by the dope of P₂O₅and the phase transformation of dicalcium orthosilicate.