高温固相法合成R_(2-x)(MoO_4)_3∶xEu~(3+)(R=Y,Gd)红色荧光粉的研究

采用高温固相法合成R2-x(MoO4)3∶xEu3+(R=Y,Gd)系列红色荧光粉.研究了煅烧温度、助熔剂的含量和Eu3+的掺杂量对样品发光性能的影响,并对样品的物相组成、激发和发射光谱进行分析.结果表明,样品Gd0.6(MoO4)3∶1.4Eu3+在800℃左右煅烧时呈单斜晶结构,当煅烧温度提高到950℃左右,呈正交斜晶结构;样品Y0.2(MoO4)3∶1.8Eu3+在800℃左右煅烧时已经完全形成了正交结构,当煅烧温度升高到1000℃左右时,其正交结构得到保持,没有发生相变.其中,助熔剂NH4Cl的含量占样品总量的3%,煅烧温度为1000℃,保温3h得到的样品Gd0.6(MoO4)3∶1.4Eu3+和Y0.2(MoO4)3∶1.8Eu3+的发光性能达到最佳.另外,由激发和发射光谱分析表明,该荧光粉可以被近紫外光(395nm)和蓝光(465nm)有效激发,发射峰值位于612nm的红光,对应于Eu3+离子的5 D0→7 F2跃迁,是一种可应用在紫外光和蓝光芯片激发产生白光LED的红色荧光粉.

Study on the Preparation of Red Phosphor R2-x (MoO4) 3 ∶ xEu3+(R＝Y, Gd) by Solid-State Reaction Method

A red emitting phosphor R2-x(MoO4)3:xEu3+(R=Y,Gd) was synthesized by solid-state reaction.The effects of the sinter temperature,flux content and Eu3+ doping concentration on luminescent properties were studied by XRD and photoluminescence(PL) spectra.The results indicated that the Gd0.6(MoO4)3∶1.4Eu3+ have two structures,monoclinic in 800 ℃ and the orthorhombic in 950 ℃,but there is only the orthorhombic in Y0.2(MoO4)3∶1.8Eu3+ preparaed in 800 ℃ and 1000 ℃.The intensity will reach the strongest of Gd0.6(MoO4)3∶1.4Eu3+ and Y0.2(MoO4)3∶1.8Eu3+ when the NH4Cl is the appropriate flux and its most suitable mass fraction is 3%,the sinter temperature is 1000 ℃ and sinter time is 3 h.The results show that this phosphor can be excited by UV light of 395 nm and blue light of 465 nm,also emit red light at about 612 nm,which attribute to the intrinsic transition from 5D0 to 7F2 of Eu3+.The phosphor may be a better phosphor candidate for solid-state lighting applications.