MGd2(WO4)4∶Sm3^+(M=Sr2^+,Ba2^+)荧光粉的合成及发光性能研究

Synthesis and photoluminescence property of MGd2(WO4)4∶Sm3^+ phosphor

采用高温固相法合成了一种新型红色荧光粉MGd2(WO4)4∶Sm3^+(M=Sr2^+,Ba2^+)。利用X射线衍射仪、扫描电镜和荧光分光光度计对样品性能进行分析。结果表明:MGd2(WO4)4∶Sm3^+(M=Sr2^+,Ba2^+)荧光粉呈三方晶系结构,其中SrGd(2-x)(WO4)4∶xSm3^+的激发光谱在404nm处有较强的吸收峰,能同紫外LED芯片很好相匹配。在404nm激发下的发射光谱,其主峰位于645nm处的特征跃迁,对应4G5/2→6H7/2跃迁。当Sm3^+掺杂浓度x=0.1时,SrGd1.9(WO4)4∶0.1Sm3^+发光强度最强,而后随着Sm3^+掺杂浓度过量会出现浓度淬灭现象。进一步探讨Ba2^+掺杂浓度对发光强度的影响,在404nm的激发波长下,Sr0.2Ba0.8Gd1.7(WO4)4∶0.3Sm3^+的发光强度高于SrGd1.7WO4∶0.3Sm3^+,且Sr0.2Ba0.8Gd1.7(WO4)4∶0.3Sm3^+最强峰位于645nm处。通过光学描绘软件(CIE)计算得到,当Sm3^+掺杂量浓度x=0.1时,SrGd1.9(WO4)4∶0.1Sm3^+红色显示最好。

A novel MGd2(WO4)4∶Sm3^+(M=Sr2^+,Ba2^+)red phosphors were synthesized by high temperature solid state reaction.The crystal structure,morphology and luminescent properties were investigated by XRD,SEM and photoluminescence spectra,respectively.The results shown that the phosphors was belong to rhombohedral crystal structure,and SrGd(2-x)(WO4)4∶xSm3^+exhibited strong excitation spectra at 404 nm,which matched well with nearUV LED chips.Upon excitation at 404 nm,the strongest peak locates at 645 nm corresponding to the 4G5/2→6H7/2 transition of Sm3^+.The luminescent intensity of SrGd2(WO4)4∶Sm3^+increases with the increase of Sm3^+content,reaches the maximumwhen the doping of Sm3^+was 0.1.The phenomenon of concentration quenching occured when Sm3^+doping concentration was excess,and the luminescent intensity attenuated.Compared with SrGd2(WO4)4∶Sm3^+,the emission intensity of SrBaGd1.7(WO4)4∶0.3 Sm3^+was increased obviously.As regards the influence of Ba2^+concentration on the luminescent property,the highest emission intensity on the 645 nm was exhibited when x was 0.3.Moreover,the red chromaticity coordinate of the samples was closer to the Commission International de L’Eclairage(CIE)chromaticity coordinates.