Li^+增强Ho^(3+)/Yb^(3+):Y_2O_3纳米晶的上转化发光研究

Up-conversion luminescence of Y_2O_3:Ho^(3+)/Yb^(3+) nanocrystals with Li^+ ions enhancement

采用凝胶溶胶法制备了不同浓度的Y2O3:Ho3+/Yb3+/Li+纳米晶,并且系统研究了不同掺杂浓度对上转化荧光现象的影响。首先,通过XRD图形判断了晶体结构的生成,再通过980 nm的激光器和荧光光谱仪测得的光谱图,发现了位于520~579 nm的绿光、635~674 nm的红光等两条很强的可见光,还有一条较弱的位于743~775 nm的近红外发光。最后,通过与能级图比较和分析可以得出:它们分别是5F4/5S2→5I8,5F5→5I8和5F4/5S2→5I7荧光跃迁。可以看出:在掺杂入Li+之后,上转化荧光得到了极大增强。

Different concentrations Y2O3：Ho^3＋/Yb^3＋Li^＋ nanocrystals were prepared by sol-gel method,and the influence of different Li＋ concentrations on the up-conversion photoluminescence of the Y2O3：Ho^3＋/Yb^3＋Li^＋ nanocrystals was studied.First,through the XRD graphics of crystal structure formation,and the spectra measured by fluorescence spectrometer under 980 nm lasers diode,strong fluorescence in green（534-570 nm） and red（635-674 nm） region of spectrum was observed.Finally,through the comparison and analysis of the energy graph,it is shown that they are the 5^F4 /5^S2→5^I8 and 5^F5→5^I8 transition of Ho^3＋ ion respectively in the green（520-579 nm） and the red（635-674 nm） region of spectrum.There is a weak fluorescence in the near infrared（743-775 nm） region of spectrum,which is the 5F4 /5S2→5I7 transition of Ho^3＋.The up-conversion intensity emitted by Ho^3＋ is greatly enhanced when Li^＋ is added to the Ho^3＋/Yb3^＋ co-doped Y2O3 nanocrystals.