Li^+掺杂对GdF3:Ho^3+/Yb^3+纳米晶上转换发光影响的研究

Study of the Effect of Li^+ Doping on Upconversion Luminescence of GdF_3: Ho^(3+)/Yb^(3+) Nanocrystals

本文采用水热法成功制取不同浓度的Gd F3:Ho3+/Yb3+纳米晶,并改变掺杂的Li+浓度、F源和EDTA-2Na量,研究其对上转换发光的影响。X射线衍射仪(XRD),傅立叶变换红外光谱(FT-IR),热重-差热分析仪(TG-DTA),场发射扫描电镜(FESEM)以及荧光分光光度计等对其结构和发光性能进行了表征。在980nm激发二极管激发下,发现位于520~560nm的绿光、630~670nm的红光两条可见光。结果证明,在其他条件一致情况下,Li+掺杂浓度为7.5mol%,EDTA-2Na为2mmol或NH4F为9mmol的发光效果最好。其中,Li+掺杂浓度为7.5mol%时,较未掺杂的绿、红光强度分别增强了5倍、2倍。

Different concentrations Gd F3： Ho^（3 ＋）/ Yb^（3 ＋）nanocrystals were prepared by hydrothermal method. The effect of the doping concentration of Li＋,the amount of EDTA- 2Na or the source of F any on the up- conversion luminescence were study. The structure and the luminescent properties of the nanocrystals were characterized by X- ray diffraction（ XRD）,Thermogravimetric- differential thermogravimetric analysis（ TG- DTA）,Fourier Transform Infrared（ FT- IR）,field emission scanning electron microscope（ FE- SEM） and fluorescence spectrometer. Under the laser diode excitation at 980 nm,visible light in the green（ 560- 570 nm） and the red（ 630- 670nm） region of spectra was observed. It turns out that doping concentration of 7. 5mol% of Li＋,2 mmol of EDTA- 2Na and 9 mmol of NH4 F luminescence effect is best in the other conditions. Compared with the undoped one,the green and red emission intensity of the microcrystals codoped with 7. 5mol% Li＋were enchanced by 5 times and 2 times,respectively.