白光LED用MSrAl_3O_7:Eu^(2+)(M=Y,La,Gd)绿色发光材料合成及其光学性能

Synthesis and optical properties of green-emitting MSrAl_3O_7:Eu^(2+)(M=Y,La,Gd) phosphors for white light-emitting diodes

采用传统的高温固相合成技术制备出一系列组成为MSrAl3O7:Eu2+(M=Y,La,Gd)的新型绿色发射荧光体。通过X射线衍射(XRD)研究其晶体结构发现:MSrAl3O7:Eu2+系列荧光体属于M2O3-SrO-Al2O3赝三元体系的稳定结晶相。荧光光谱测试表明:MSrAl3O7:Eu2+(M=Y、La、Gd)材料均是优良的白光LED用绿色荧光体,可被近紫外(300～450nm)有效激发,产生较强的绿色发射光,发射主峰位于517nm左右,样品的紫外-可见(UV-vis)光谱进一步证实了其有效吸收近紫外光的特征。研究还发现,在MSrAl3O7:Eu2+(M=Y、La、Gd)系列荧光体中,LaSrAl3O7:Eu2+具有最强的绿色发射光,进一步地比较不同温度下LaSrAl3O7:Eu2+材料的结构与光谱特性表明,1400℃合成的样品具有稳定的结构和最佳的发光性能。

A series of green-emitting phosphors with compositions of MSrAl3O7 ： Eu^2＋ （M=Y, La,Gd） were prepared by the traditional solid-state method. Their structural phases were investigated using X-ray diffraction （XRD） technique,and it was found that these phosphors belonged to some stable crystal phase in M2O3-SrO- Al2O3 pseudo-ternary system room-temperature optical properties for MSrAl3 O7 ： Eu^2＋ （M = Y, La, Gd） phosphors were analyzed by the UV-vis diffuse reflectance spectroscopy, excitation and emission spectroscopy. It was found that,MSrAl3O7 ： Eu^2＋ （M= Y, La, Gd） phosphors showed broad excitation in the near ultraviolet region （300-450 nm）,and they all exhibited green light with peak wavelength at 517nm,which indicated that they were promising as the green component of light-conversion phosphors for white LEDs. Further investigations for MSrAl3O7 ： Eu^2＋ （M= Y, La,Gd） phosphors indicated that MSrAl3O7 ： Eu^2＋ showed the strongest green emission,and the optimum reaction temperture was 1400℃ ,at which stable crystal structure and excellent optical properties could be obtained.