发光学报, 2019, 40 (2): 143, 网络出版: 2019-03-11
纳米材料的控制合成及其上转换发光性质
Controllable Synthesis and Upconversion Luminescence Properties of Yb3+/Er3+ Codoped (MLaFn)x (M=0,K;n=3,4;x=1,1.5) of Nanomaterials
水热与溶剂热结合法 KF/RE的量比 稀土氟化物 上转换发光 hydro/solvothermal method molar ratio of KF/RE rare earth fluoride upconversion luminescence
摘要
采用水热与溶剂热结合的方法, 在乙二醇-正己醇体系中, 通过调节KF与RE(RE=La, Yb, Er)的量比、反应温度和反应时间实现了由LaF3(六角相)到KLaF4(立方相、六角相)晶型的控制合成。借助透射电子显微镜(TEM)和X射线粉末衍射(XRD)对样品的结构和微观形貌进行表征。结果表明, 当KF/RE比例为2.25时, 制备的样品为片状的六角相LaF3纳米颗粒; 当KF/RE比例为3.00时, 得到具有近似球形的立方相KLaF4纳米颗粒; 当KF/RE比例为4.25时, 得到了六角相(KLaF4)1.5纳米颗粒。上转换发射光谱显示: 所有的样品在近红外光(980 nm)激发下, 均有3个明显的发射峰, 在522 nm、544 nm处分别对应于Er3+的4S3/2, 2H11/2→4I15/2能级跃迁, 655 nm处属于Er3+的4F9/2→4I15/2能级跃迁。
Abstract
Upconversion nanocrystals(UPCNs) from hexagonal phase LaF3 (β) to cubic phase KLaF4(α) or hexagonal phase(KLaF4)1.5(β) were prepared by simply tuning the molar ratio of KF to RE(RE=La, Yb, Er), reaction temperature and reaction time in ethlene glycol(EG) and 1-hexanol (HA) mixed solvents via a facile hydro/solvothermal method. The β-LaF3 to α-KLaF4 or β-(KLaF4)1.5transformation process was studied by X-ray diffraction(XRD), fluorescence spectrophotometer with an external 980 nm single-wavelength diode laser and transmission electron microscopy(TEM) techniques. The results indicate that the hexagonal phase of LaF3 nanosheet was synthesized when the ratio of KF/RE was 2.25. With the ratio of KF/RE increased to 3.00, the approximate spherical cubic phase of KLaF4 was obtained. The cubic phase of KLaF4 completely transforms into the hexagonal phase of (KLaF4)1.5 when the ratio of KF/RE was 4.25. The red and green emission are corresponding to the transitions 4S3/2, 2H11/2→4I15/2(Green) at 522 nm and 544 nm, 4F9/2→ 4I15/2(Red) at 655 nm of Er3+ ions, respectively.
刘媛媛, 德格吉呼, 王仙. 纳米材料的控制合成及其上转换发光性质[J]. 发光学报, 2019, 40(2): 143. LIU Yuan-yuan, DE Ge-ji-hu, WANG Xian. Controllable Synthesis and Upconversion Luminescence Properties of Yb3+/Er3+ Codoped (MLaFn)x (M=0,K;n=3,4;x=1,1.5) of Nanomaterials[J]. Chinese Journal of Luminescence, 2019, 40(2): 143.