紫外光激发Ce^(3+)掺YVO_4蓝光发射性能研究  

Blue-emitting Properties of Ce^(3+) Doped YVO_4 under Ultraviolet Excitation

作　　者：张守超[1] 阮永丰[2] 贾国治[1] 冯志辉[1] 刘枝朋[1] 裴利斌 

机构地区：[1]天津城建大学理学院,天津300384 [2]天津大学理学院,天津300072

出　　处：《无机材料学报》2014年第10期1067-1072,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金(11247025);天津市自然科学基金(11JCYBJC05200)~~

摘　　要：利用提拉法生长了YVO4和掺2.0at%CeO2(或Ce2(CO3)3)的YVO4:Ce3+晶体。样品的XRD测试表明Ce3+代替Y3+进入晶格,Ce3+的加入并没有影响YVO4的晶格结构。XPS测试显示YVO4:Ce3+晶体中Ce离子3d分裂为882.0、885.8、902.9、908.0和915.9 eV等5个峰,峰位表明样品中铈离子是以Ce3+和Ce4+两种价态形式存在。YVO4和YVO4:Ce3+激发谱都呈现出260~360 nm宽带激发,此激发带源于基质中VO43-离子团的配体O到V的电荷迁移吸收。使用325 nm的紫外线激发时,两种样品均可发出以440 nm为中心的宽带蓝光,其中YVO4发射峰应归属于VO43-离子团中3T2→1A1和3T1→1A1跃迁;而YVO4:Ce3+的蓝光发射则来源于Ce3+的5d→4f的跃迁。分析可知YVO4:Ce3+中VO43-的π轨道和Ce3+的电子波函数能有效地重叠,使得VO43-和Ce3+可通过交换作用有效地向Ce3+传递能量,可大幅提高Ce3+的蓝光发射强度。实验结果显示YVO4:Ce3+可作为UV-LED管芯激发的白光发光二极管用高亮度蓝色发光材料。YVO4 and YVO4：Ce^3＋ single crystals doped with 2.0at% CeO2（or Ce2（CO3）3） were grown by using the Czochralski method. XRD pattern shows that Ce^3＋ ion enters the YVO4 lattice by occupying the Y^3＋ sites and the YVO4 crystal structure change little by the addition of Ce ions. The X-ray photoelectron spectroscopy（XPS） shows that the Ce（3d） peak splits into five peaks located at 882.0, 885.8, 902.9, 908.0 and 915.9 eV, which indicates that the Ce^3＋ and Ce^4＋ ions coexist in both kind of samples. The excitation spectra of YVO4 and YVO4：Ce^3＋ crystals are both in the range from 260 nm to 360 nm, due to the charge transfer transition of the O^2--V^5＋ ion pairs of VO4^3-polyhedron. YVO4 and YVO4：Ce^3＋ single crystals radiate a wideband blue light centered at 440 nm when excited by 325 nm ultraviolet light, the former corresponds to ^3T2→^1A1 and ^3T1→^1A1 transition of VO4^3-, while the latter corresponds to 5d→4f transition of Ce^3＋. In YVO4： Ce^3＋ crystal, the wave functions of Ce^3＋ overlaps effectively to the π orbital of VO4^3-, via this interaction the energy can be transfer effectively from VO4^3- to Ce^3＋, so that the blue-emitting intensity of Ce^3＋ is improved significantly. Experimental results show that YVO4： Ce^3＋ crystal is a potential blue-emitting material for white-emitting LED under ultraviolet excitation.

关 键 词：YVO4:Ce^3+ 蓝光发射 紫外激发 能量传递 白光LED 

分 类 号：TQ174[化学工程—陶瓷工业]