Eu^3+/Sm^3+共掺K2Gd(WO4)(PO4)荧光粉的发光性能及热稳定性研究

Photoluminescence Properties and Thermal Stability of Eu^(3+)/Sm^(3+)Co-doped K_2Gd(WO_4)(PO_4) Phosphors

采用高温固相法制备了K_2Gd_(1-x-y)(PO_4)(WO_4):x Sm^(3+),y Eu^(3+)新型红色荧光材料,通过利用X射线衍射谱(XRD)、荧光光谱对其结构及发光性能进行了研究。结果表明,稀土离子S^(3+)的掺入没有改变荧光粉的晶相;样品的激发光谱在394 nm有很强的激发峰,与近紫外LED芯片匹配,且Eu^(3+)的~5D_0→~7F_2电偶极跃迁表现出616 nm有较好的红光发射,Eu^(3+)的最佳掺杂量(摩尔分数)为y=0.3;Sm^(3+)进入晶格后,激发峰明显增强和变宽,表明Sm^(3+)对Eu^(3+)的发光起到敏化作用;K_2Gd_(0.68)(PO_4)(WO_4)∶0.3Eu^(3+),0.02Sm^(3+)样品在150℃时发光强度仍为初始温度的78%,具有良好的热稳定性且色纯度高,是一种潜在的白光LED用荧光粉。

The K2Gd1-x-yEuy(PO4)(WO4)∶xSm3+novel red-emitting phosphors were prepared by a high temperature solid state reaction,the structure and luminescent properties of these powdered samples were characterized by X-ray diffraction and photoluminescence spectra,respectively.The results showed that the doping of rare earth ions Sm3+does not change the crystalline phase of phosphors and exhibit strong excitation spectra at 394 nm,which matched well with near-UV LED chips.The 5D0→7F2 dipole transition of Eu3+showed good red emission at 616 nm,the optimal mole concentration of Eu3+is 0.3.The excitation peak is significantly enhanced and widened when Sm3+enters the lattice,indicating that Sm3+is sensitive to the luminescence of Eu3+.Moreover,the photoluminescence exhibits a favorable thermal stability and color purity.These outstanding characteristics indicated that K2Gd1-x-yEuy(PO4)(WO4):xSm3+phosphors might have potential applications for white LED.