单晶体α-NaYF_4∶Dy^(3+)的制备及光谱特性（英文）  

Growth and Optical Spectra of Dy^(3+) Dopedα-NaYF_4 Single Crystal

作　　者：姜永章 夏海平[1] 张加忠[1] 杨硕[1] 江东升[1] 王成[1] 冯治刚[1] 张健[1] 谷雪梅[1] 章践立[1] 江浩川[2] 陈宝玖[3] 

机构地区：[1]宁波大学光电子功能材料重点实验室,浙江宁波315211 [2]中国科学院宁波材料技术与工程研究所,浙江宁波315211 [3]大连海事大学物理系,辽宁大连116026

出　　处：《光子学报》2015年第8期121-126,共6页Acta Photonica Sinica

基　　金：The National Natural Science Foundation of China(Nos.51472125,51272109);K.C.Wong Magna Fund in Ningbo University

摘　　要：以氟化钾(KF)作为助熔剂,选用70~90℃/cm的固液界面温度梯度,通过改进的助熔剂-布里奇曼方法生长出了Dy3+离子掺杂的α-NaYF4单晶体.测试了样品的X射线粉末衍射,吸收光谱,激发光谱,以及在不同紫外光激发下的发射光谱,分析了样品的的物相和光谱特性.应用色度学理论计算了Dy3+离子掺杂α-NaYF4单晶的色度坐标和色温.结果表明:当原料组份配比为30NaF-18KF-52YF3时,有利于大尺寸晶体生长.原料中KF的加入起到助熔剂作用,它改变了NaF-YF3二元系相图并且降低了α-NaYF4的熔点,使得α-NaYF4能从熔融的NaF-KF-YF3混合物中结晶出来,最后生长出透明的α-NaYF4单晶体.实验发现大多KF被排析在生长后期的晶体顶端,KF的加入没有对α-NaYF4单晶体的结构产生影响.在348nm紫外光激发下,单晶体可发射出蓝光约479nm,黄光约571nm以及弱的红光约659nm.其中1.299mol%Dy3+掺杂浓度的α-NaYF4单晶体发射的蓝、黄与红光可耦合出色坐标x=0.285,y=0.338以及色温为8 065K的白光.这些新型材料在紫外激发的白光二极管领域具有潜在的应用.The Dy3＋dopedα-NaYF4 single crystals were synthesized by a modified Bridgman method under the conditions of taking KF as an assistant flux and a temperature gradient（70~90 ℃/cm）at the solid-liquid interface.X-ray diffraction,absorption spectra,excitation spectra,and emission spectra were measured to investigate the phase and spectrum properties of the crystals.The chromaticity coordinates and color temperature of crystals were calculated based on Colorimetry theories. Many growing experiments demonstrate that the chemical compositions of 30NaF-18KF-52YF3（molar ratio）arebeneficial to obtain bigα-NaYF4 single crystals.The introduction of KF changed the phase equilibrium between NaF and YF3 completely and lowered the melting point ofα-NaYF4,resulting into crystallization ofα-NaYF4 just from the mixture when it is cooled.Most of KF was excluded on the top of crystals which grew at the final stage of crystal growth.The introduction of flux KF did not change the structure ofα-NaYF4 single crystals.The emission blue 479 nm,yellow 571 nm and weak red 659 nm could be obtained simultaneously under the excitation of ultraviolet lights.A white light emission from the coupling of the above three lights with chromaticity coordinates of x =0.285,y=0.338,color temperature Tc=8 065 Kcould be obtained from 1.299mole% Dy3＋dopedα-NaYF4 single crystal when excited by a 348 nm light.This indicates that Dy3＋dopedα-NaYF4 single crystals can be a potential candidate for white light emitting diode excited by ultraviolet light.

关 键 词：光学材料 光谱 布里奇曼方法 α-NaYF4单晶体 白光发射 紫外光 

分 类 号：O782[理学—晶体学] O734