Sr1-x Al1＋y Si4-y N7-y Oy：xEu^2＋橙色荧光粉的合成及发光特性研究

Synthesis and Photoluminescence Properties of Orange-Emitting Sr_(1-x)Al_(1+y)Si_(4-y)N_(7-y)O_y: xEu^(2+) Phosphors

采用常压高温固相法合成一种新型的氮氧化物橙色荧光粉SrAl1+ySi4-yN7-yOy:Eu2+。结合X射线衍射(XRD)、扫描电镜(SEM)和荧光光谱等分析手段,研究了荧光粉的组分配比变化对其物相结构的影响,结果发现当0≤y≤0.225时,该物质属于SrAlSi4N7结构。结合对离子半径及晶格常数变化等的分析,推断晶格中氧是以Al-O键取代了晶格中的Si-N键的方式而存在。通过对该荧光粉的光色特性研究发现,SrAl1+ySi4-yN7-yOy:Eu2+荧光粉可被近紫外到可见光有效激发,产生580~600 nm的橙光发射。对比Sr0.9Al1.225Si3.775N6.775O0.225:Eu0.1荧光粉和Sr0.9AlSi4N7:Eu0.1荧光粉的斯托克斯位移发现,Al-O的引入使得Sr0.9Al1.225Si3.775N6.775O0.225:Eu0.1荧光粉的非辐射弛豫几率相对较小,从而具有相对更高的热稳定性。因此,SrAl1+ySi4-yN7-yOy:Eu系列荧光粉是一款颇具前景的白光LED用橙色荧光粉。

A novel orange-emitting Sr1-xAl1＋ySi4-yN7-yOy：xEu^2＋ phosphor was synthesized by high temperature solid-state reaction. The effect of the composition changes on crystal structure formation was studied by means of X-ray diffraction （ XRD）, scanning electron microscope （SEM） and fluorescence spectra. It was revealed that the as-prepared phosphors displayed similar XRD patterns as SrAlSi4N7 when 0≤y≤0. 225. It could be inferred, from ionic radius and lattice constants variations, that Sr1-xAl1＋ySi4-yN7-yOy：xEu^2＋ solid solutions was established by replacing some of the Si-N bonds with A1- O bonds in the SrA1Si4N7 structure. Photoluminescence （PL） results showed that the phosphors could be efficiently excited by near UV-visible light, and exhibited a broad emission band from 580 - 600 nm. In addition, Sr0.9 Al1.225 Si3775 N6.775 O0.225 ： EU0. 1 phosphor showed higher thermal stability than Sr0.9 AlSi4N7 ： Eu0. 1 phosphor due to the Al - O induced lower probability of the non-radiative transition according to Stokes shift values. Therefore, all results indicated that this newly developed Sr1-xAl1＋ySi4-yN7-yOy：xEu^2＋ phosphors showed high potential as orange-emitting phosphors conversion for white LED applications.