合成了一个双核铕的配合物,[HN(CH3CH2)3]2[Eu2(bdb)4]·CH3CH2OH,{H2bdb=4,4'-双(4",4",4"-三氟代-1",3"-二氧代丁基)邻三联苯}.该配合物在紫外和近紫外光激发下发出铕离子特征红光.配合物中三价铕离子的5D0激发态寿命为704μs,寿命曲线很好地和单指数衰减拟合曲线相吻合.监控614nm的红光发射,激发光谱位于250~420nm范围.在395nm处具有很强的激发强度,该配合物能够被395nm发射的InGaN芯片发出的近紫外光激发而发红光.变温光致发光测定表明,该配合物的温度淬灭效应很小.当温度升高到200℃,依然发射出很强的红光.配合物热稳定性达到260℃.发光性质和热稳定性满足制备LED器件的要求.将该配合物与395nm发射的InGaN芯片组合制备了红色发光二极管,当配合物和硅树脂的质量比为1:20,工作电流为20mA时,红色发光二极管的色坐标为x=0.61,y=0.31,发光效率为3.64lm/W.将该配合物与发蓝绿光的二-2-(2'-羟基苯基)苯并噻唑锌混合涂布在395nm发射的InGaN芯片上制备成了白光发光二极管,合适的质量比为铕配合物:锌配合物:硅树脂=1:1:25.工作电流为20mA时,色坐标x=0.32,y=0.32;色温Tc=6026K;显色指数Ra=81;发光效率为1.26lm/W.结果表明,该配合物是制备半导体高显色指数白光LED的一种红光材料.
A dinuclear Eu(Ⅲ) complex [HN(CH3CH2)3]2[Eu2(bdb)4]·CH3CH2OH [H2bdb=4,4'-bis (4",4",4"-trifluoro-1",3"-dioxobutyl)-o-terphenyl] was synthesized.The complex emits bright red luminescence,characteristic of the 5 D 0 → 7 F J (J=0~4) emission peaks of Eu 3+ under near UV irradiation.The luminescence lifetime of the emitting 5 D 0 level of the complex is 704 μs.The decay curve can be fit with a single exponential model.Monitored at 614 nm,excitation wavelength is located in the range of 250~420 nm.Excitation intensity of the complex is strong enough at 395 nm and the complex can be well excited by the 395 nm emission light of InGaN chip.The investigation of the temperature dependence of PL intensity for the Eu(Ⅲ) complex shows that the complex can keep up with good emission intensity as the temperature rises to 200 ℃.The thermogravimetric analyses curve for complex shows the complex is up to 260 ℃.The luminescence properties and thermostability meet the requirements of fabrication of LED device.Bright red conversion light-emitting diode (LED) device was fabricated by coating complex onto 395 nm InGaN chip.When the mass ratio of the europium complex to the silicone is 1:20,the LED CIE chromaticity coordinates is x=0.61,y=0.31.The luminescence efficiency of device is 3.64 lm/W under 20 mA forward bias.White conversion LED was fabricated by coating this europium complex and bis(2-(2'-hydroxyphenyl)benzothiazolate)zinc [Zn(btz)2] onto 395 nm InGaN chip.The appropriate mass ratio to obtain white light of the europium complex,[Zn(btz)2] and the silicone is 1:1:25,the LED CIE (Commission International d'Eclairage) chromaticity coordinates is x=0.32,y=0.32,Tc=6026 K,R a=81 under 20 mA forward bias.The luminescence efficiency of device is 1.26 lm/W.The results indicate that the europium complex can act as red component in the fabrication of white LEDs.