中文摘要：

采用高温固相法合成出系列绿色Ca5-xEux（SiO4）2F2荧光粉,并对其发光特性进行了研究。Eu2＋离子在Ca5（SiO4）2F2基质中可被250～440 nm光有效激发发出绿光,适合作为UV-LED用绿色荧光粉。浓度猝灭实验结果表明,Eu2＋离子的最佳掺杂摩尔分数为0.15,通过计算推测出Eu2＋离子在Ca5-xEux（SiO4）2F2中的能量转移机制应该为偶极-偶极相互作用。温度猝灭特性表明,450 K时的发射强度约为10 K时的35%。不同温度下Eu2＋离子的荧光寿命结果表明,随着温度的不断升高,荧光寿命不断缩短。

英文摘要：

A series of new green-emitting phosphors,Eu2＋-activated Ca5-xEux（SiO4）2F2 were synthesized at 1 223 K by conventional high-temperature solid-state reactions under reductive atmosphere.And the photoluminescence excitation,diffuse reflectance and emission spectra,concentration quenching process,temperature dependence of luminescence and lifetime of phosphors were systematically investigated.The excitation spectrum shows that Ca5（SiO4）2F2∶Eu2＋ can be efficiently excited by the incident lights of 250～440 nm,perfectly matching with the emissions wavelength of near-UV LEDs.The emission intensity is influenced by the Eu2＋ content,and the optimal doping mole fraction is about 0.15.The concentration quenching mechanism was verified as dipole-dipole interaction and the value of the critical transfer distance was calculated as 1.5 nm.The temperature dependent emission spectra in the temperature range of 10~450 K show that the emission intensity at 450 K is 35% of the emission intensity at 10 K.At room temperature,the lifetimes of Eu2＋ ions in Ca4.85Eu0.15（SiO4）2F2 phosphors are determined to be 1.78 μs and 7.79 μs,respectively.All of these indicate that Ca5（SiO4）2F2∶Eu2＋ is a promising green phosphor candidate for phosphor-converted white LEDs.