Ce^(3+)浓度对YVO_4:Ce^(3+)晶体发光性能的影响  

Ce Doping Concentration on Luminescence Property of YVO_4:Ce^(3+) Crystals

作　　者：杨广武[1,2] 杨瑞霞[1,3] 张守超[2] 朱飞[2] YANG Guang-Wu YANG Rui-Xia ZHANG Shou-Chao ZHU Fei(School of Electronic and Information Engineering, Hebei University of Technology, Tianjin 300401, China School of Science, Tianjin Chengjian University, Tianjin 300384, China Tianjin Key Laboratory of Electronic Materials and Devices, Tianjin 300401, China)

机构地区：[1]河北工业大学电子信息工程学院,天津300401 [2]天津城建大学理学院,天津300384 [3]天津市电子材料与器件重点实验室,天津300401

出　　处：《无机材料学报》2016年第10期1073-1080,共8页Journal of Inorganic Materials

基　　金：国家自然科学基金(11504261);河北省自然科学基金(F2014202184);天津市自然科学基金(15JCZDJC37800)~~

摘　　要：利用提拉法生长了掺杂浓度为1.0at%~10.0at%的YVO_4:Ce^(3+)单晶,XRD分析显示Ce^(3+)的掺入没有改变晶体结构。晶体的激发和发射谱测试表明,在325 nm激发下YVO_4:Ce^(3+)发射出峰值在445 nm的蓝光和620 nm附近的红光。蓝光发光强度随Ce^(3+)浓度增加而增强,当浓度为8.0at%时达到最强,10.0at%时出现浓度淬灭,发光减弱;红光则随着Ce^(3+)浓度的增加而持续增强。通过实验分析推测蓝光来源于Ce^(3+)电子从激发态~2D_(3/2)到基态~2F_(5/2)的跃迁,而红光则是由于V^(4+)的电子能级跃迁而形成的。XPS测试显示部分Ce^(3+)失去电子被氧化成为Ce^(4+),失去的电子大部分被V^(5+)捕获形成V^(4+)。V^(4+)的d轨道分裂为三个轨道单态~2A_1、~2B_1、~2B_2和一个轨道简并态~2E等4个能级,基态为~2B_2。V^(4+)中电子通过能量传递、辐射跃迁和无辐射跃迁等过程,可以实现波长在620 nm附近的红光发射以及在620 nm激发下的451 nm蓝光上转换发光。实验证实了上转换发光为双光子过程。研究结果对紫外激发下YVO_4:Ce^(3+)红、蓝光发光行为提供了理论支撑。Pure YVO4 crystal and YVO4 crystal doped with different Ce concentrations were grown by Czochralski method. XRD pattern shows Ce^3＋ ion enters the YVO4 lattice by occupying the y^3＋ site and the crystal structure was not significantly changed. The detection of UV excitation spectrum and emission spectrum of YVO4： Ce3＋ at room temperature showed that excited at 325 nm the YVO4： Ce^3＋ emits two spectra. The main emission spectrum at 445 nm is a broadband peak, caused by transition of 2D3/2→2Fs/2 of Ce^3＋. The other one is a weak peak emission centered around 620 nm, which presents the emission of V4＋. With increase of Ce mole fraction from 1at% to 8at%, the blue emission intensity gradually increases to a maximum value. As Ce fraction increases to 10.0at%, the emission in- tensity decreases gradually, indicating an obvious concentration quenching. The red emission intensity gradually increases to a maximum value when Ce fraction increases to 10.0at%. Detection by X-ray photoelectron spectros- copy （XPS） shows that Ce^4＋ and V4＋ ions coexist in YVO4：Ce^3＋, which may result from some of the Ce^3＋ losing electrons to be oxidized into Ce^4＋, and most of them being captured by the V5＋ ions and, therefore, resulting in V^5＋→V^4＋ transformation. Based on V^4＋ d orbital splitting into 2Ab 2B1, 2B2, and 2E, the 620 nm red emission under 325 nm and 450 nm excitation probably originated from electronic transitions between the conclusion, present analytical data of the luminescence spectra of YV04： Ce3＋ provide a YVOa：Ce^3＋ emitting red light and blue light simultaneously under UV excitation. V4＋splitted d orbits. In theoretical support for YVO4：Ce^3＋ emitting red light and blue light simultaneously under UV excitation.

关 键 词：铈离子 上转换发光 V^4+ 能量传递 红光发射 

分 类 号：TQ174[化学工程—陶瓷工业]