Rongjun XIE
,
Tianliang ZHOU
,
Kohei TAKAHAHIS
,
Naoto HIROSAKI
应用化学
doi:10.11944/j.issn.1000-0518.2016.08.160240
GaN-based white light-emitting diode(LED) is now an emerging backlight technology for large color gamut and high efficiency liquid crystal displays. In this technology, phosphors are key materials to control the color-space coverage, luminous efficiency, and lifetime of the backlight units, which are required to have a desired emission and a narrow emission band. β-Sialon:Eu2+(sialon:silicon aluminum oxynitride, Si6-zAlzOzN8-z) is such a green phosphor because it has an emission band centered at 525~545 nm and a small band width(~55 nm). This contribution overviews the synthesis, luminescence, electronic and crystal structure, reliability and applications of β-sialon:Eu2+. From both structure calculations and experimental observations, Eu2+ is seen to be accommodated into a large void along the c-axis, and coordinated to six nitrogen/oxygen atoms at an equivalent distance. The narrow emission band is thus ascribed to the high symmetry of the local structure of Eu2+. Both of the emission band and the band width of β-sialon:Eu2+ can be tuned by tailoring the composition(e.g., the z value), and β-sialon:Eu2+ with shorter wavelengths and narrower bands can be achieved at lower z values. Combined with other red phosphors, β-sialon:Eu2+ enables to produce wider color gamut backlights(15% up) than the conventional yttrium aluminum garnet(YAG)-based ones. Both the excellent luminescence properties and reliability make β-sialon:Eu2+ to be an extremely important green phosphor for use in advanced displays.
关键词:
rare earth
,
nitride
,
beta-sialon:Eu2+
,
phosphor
,
electronic structure
,
light-emitting diode
,
backlighting
解荣军
,
周天亮
,
高桥向星
,
广崎尚登
应用化学
doi:10.11944/j.issn.1000-0518.2016.08.160240
基于氮化镓的白光发光二极管(LED)是目前一项崭新的背光源技术,广泛应用于宽色域、高光效的液晶显示屏.在此项技术中,作为关键材料的荧光粉决定着背光单元的色域范围、发光效率和可靠性,因而要求它应具合适的发射波长和窄带发射.β-sialon∶ Eu2+(sialon:silicon aluminum oxynitride(赛龙))就是一款非常适合背光应用的绿色荧光粉,这得益于其位于525 ～ 545 nm发射峰和只有55 nm狭窄的峰宽.此文回顾和综述了β-sialon∶ Eu2+的合成方法、光谱特性、电子结构、晶体结构、可靠性和它的具体应用.计算模拟和实验测试结果表明,Eu2+位于沿c轴方向的大孔道之中,并与6个最紧邻的(0,N)原子等距离配位.因而,Eu2+的狭窄发射峰源自于Eu2+局域结构的高度对称性.β-sialon∶ Eu2+的发射波长和带宽都能通过组成裁剪,即z值,进行调控;低z值组成能够实现更短波长发射和更窄带宽.与传统的基于钇铝石榴石(YAG)荧光粉的背光源相比,β-sialon∶ Eu2+再搭配红色荧光粉制备的背光源具有更宽的色域,色域范围可提高15％以上.其优异的发光性能和高可靠性使得β-sialon∶ Eu2+成为应用于先进显示屏的极其重要的绿色发光材料.
关键词:
稀土
,
氮化物
,
beta-sialon∶Eu2+
,
荧光粉
,
电子结构
,
发光二极管
,
背光源
