棒状结构NaGdF_(4):Yb^(3+),Er^(3+)上转换发光性能的研究

Upconversion luminescence of NaGdF_(4):Yb^(3+),Er^(3+)in rod-like structures

以乙二胺四乙酸二钠(EDTD-2Na)为螯合剂,采用水热法合成了棒状结构的NaGdF_(4):Yb^(3+),Er^(3+)纳米粉末。分别借助X射线衍射(XRD)、荧光光谱仪(PL)和扫描显微镜(SEM)对其晶体结构、发光强度和表面形貌进行分析和表征。探究了稀土前驱体、水热温度和水热时间的实验条件对NaGdF_(4):Yb^(3+),Er^(3+)纳米粉末上转换发光强度的影响;研究了氟源和钠源对NaGdF_(4):Yb^(3+),Er^(3+)晶体形貌和上转换发光强度的改善;同时,采用煅烧处理的方法,进一步探究样品的形貌和发光强度收到的影响。实验结果表明NH4F与NaOH作为氟源和钠源及200℃煅烧1 h得到的棒状结构NaGdF_(4):Yb^(3+),Er^(3+)的发光强度最好,色坐标(CIE)绿色发光强度从84%提升到94.88%。

The rod-shaped structure of NaGdF_(4):Yb^(3+),Er^(3+)nanopowders was created by hydrothermal method using disodium ethylenediaminetetraacetate(EDTA-2Na)as chelating agent.By using X-ray diffraction(XRD),fluorescence spectrometry(PL),and scanning electron microscopy(SEM),the crystal structure,luminescence intensity,and surface morphology of NaGdF_(4):Yb^(3+),Er^(3+)were investigated and quantified.Herein,on the converted luminescence intensity on NaGdF_(4):Yb^(3+),Er^(3+)nanopowders,the impacts of experimental conditions of rare earth precursors,hydrothermal temperature and hydrothermal time were made an effective inquiry.Fluorine and sodium sources’effects on NaGdF_(4):Yb^(3+),Er^(3+)crystal shape and upconversion luminescence intensity were investigated.Meanwhile,the effects on the morphology and luminescence intensity of the samples were further investigated using the calcination procedure.The results of the experiment indicate that the most optimal luminescence intensity of NaGdF_(4):Yb^(3+),Er^(3+)is obtained from a rod structure that using NH 4F and NaOH as fluorine and sodium sources respectively and undergone calcination at 200℃ for 1 hour.As a result,the green luminescence purity,measured through the Commission Internationale de Ieclairage(CIE),was significantly improved from 84% to 94.88%.