硫酸盐还原法制备La_2O_2S∶Yb,Er及其上转换发光性能

Up-conversion Luminescence of La_2O_2S∶Yb,Er Prepared by Sulphate Reduction Method

采用硫酸盐还原法制备了Yb、Er双掺的La2O2S粉体,考察了柠檬酸用量、前驱体煅烧温度、碳还原温度、Er3+离子浓度和Yb3+离子浓度对粉体的影响。分别采用X-射线衍射分析(XRD)、扫描电子显微镜(SEM)、比表面积分析(BET)、紫外可见光分光光度计(UVPC)和荧光光谱分析(PL)对粉体的相组成、形貌、颗粒尺寸、反射率和上转换发光性能进行表征。研究结果表明,800℃时可以得到纯相的La2(SO4)3;碳还原温度为900℃以上可以得到纯相的结晶较好的La2O2S;样品的粒径大约为100～200nm,颗粒存在一定的团聚;柠檬酸与硝酸盐的最佳摩尔比为1.5∶1;Er3+离子掺杂浓度为2mol%、Yb3+离子掺杂浓度为12mol%时粉体的上转换发光强度最强。

Yb and Er co-doped La2O2S powders were prepared by sulfate reduction method.Effects of the amount of citric acid,calcination temperature of precursor,carbon reduction temperature,Er3＋ ion concentration and Yb3＋ ion concentration on the powders were investigated.The phase composition,morphology,particle size,reflectivity and upconversion luminescence were characterized by X-ray diffractometry（XRD）,scanning electron microscopy（SEM）,specific surface area analysis（BET）,ultraviolet-visible spectrophotometry（UVPC） and phosphorescence spectrum analysis（PL）.The results show that pure La2（SO4）3 can be obtained at 800℃,pure La2O2S powder are got when carbon reduction temperature is above 900℃,the particle size is about 100～200nm,the particles have some agglomeration,as the molar ratio of citric acid and nitrate is 1.5：1,the concentration of Er3＋ is 2 mol%,the concentration of Yb3＋ is 12 mol%,the upconversion luminescent intensity was the strongest.