CAJ | 학술논문

为研究Yb~(3+)离子浓度变化对Tm~(3+)离子在蓝色波段荧光强度的影响,以NaF和La(NO_3)_3为原料,采用水热法制备了Tm~(3+)和Yb~(3+)共掺的Tm~(3+)/ Yb~(3+)∶LaF_3纳米颗粒.用X射线衍射对LaF_3纳米颗粒进行表征的结果显示,纳米晶体结构呈六方相.透射电镜的观测结果显示,纳米颗粒样品大小均匀、分散性良好.在波长为800 nm的激光激发下,观测到了上转换蓝光发射,其中包括波长为474 nm和479 nm的较强的荧光辐射(相应的跃迁为~1G_4→~3H_6)和波长位于450 nm的强度较弱的荧光发射(相应的跃迁为~1D_2→~3F_4).通过观测不同Yb~(3+)离子浓度条件下共掺Tm~(3+)/Yb~(3+)∶LaF_3样品的荧光光谱,研究了Yb~(3+)离子掺杂浓度对于Tm~(3+)离子的荧光发射的影响,并探讨了产生这种现象的原因.研究结果显示,对于~1G_4→~3H_6跃迁产生的荧光发射(474 nm),当Yb~(3+)离子浓度增大时,反向能量传递速率的增加导致了荧光强度的增大.然而,当Yb~(3+)离子浓度增大到一定程度时,Yb~(3+)离子激发态能级寿命的减少将引发荧光强度的下降.相比较而言,Yb~(3+)离子的浓度的变化对于~1D_2→~3F_4跃迁产生的位于450 nm处荧光强度的影响较弱.
위연구Yb~(3+)리자농도변화대Tm~(3+)리자재람색파단형광강도적영향,이NaF화La(NO_3)_3위원료,채용수열법제비료Tm~(3+)화Yb~(3+)공참적Tm~(3+)/ Yb~(3+)∶LaF_3납미과립.용X사선연사대LaF_3납미과립진행표정적결과현시,납미정체결구정륙방상.투사전경적관측결과현시,납미과립양품대소균균、분산성량호.재파장위800 nm적격광격발하,관측도료상전환람광발사,기중포괄파장위474 nm화479 nm적교강적형광복사(상응적약천위~1G_4→~3H_6)화파장위우450 nm적강도교약적형광발사(상응적약천위~1D_2→~3F_4).통과관측불동Yb~(3+)리자농도조건하공참Tm~(3+)/Yb~(3+)∶LaF_3양품적형광광보,연구료Yb~(3+)리자참잡농도대우Tm~(3+)리자적형광발사적영향,병탐토료산생저충현상적원인.연구결과현시,대우~1G_4→~3H_6약천산생적형광발사(474 nm),당Yb~(3+)리자농도증대시,반향능량전체속솔적증가도치료형광강도적증대.연이,당Yb~(3+)리자농도증대도일정정도시,Yb~(3+)리자격발태능급수명적감소장인발형광강도적하강.상비교이언,Yb~(3+)리자적농도적변화대우~1D_2→~3F_4약천산생적위우450 nm처형광강도적영향교약.
In order to investigate the influence of Yb~(3+)concentration on the up-converted blue fluorescence intensity of Tm~(3+) ions,the fluorescent materials of Tm~(3+) and Yb~(3+) codoped LaF_3 nanoparticles are prepared using hydrothermal method with NaF and La(NO_3)_3 as raw materials.The result of X-ray diffraction shows that the crystal structure of the prepared nanoparticles is hexagonal.The image of the transmission electron microscopy suggents that the particles are uniformly distributed and have a good dispersity.Up-converted blue emissions at 474 nm and 450 nm,which correspond to the transitions of ~1G_4→~3H_6 and ~1D_2→~3F_4 respectively,are observed when the samples are excited with 800 nm lasers.The influence of Yb~(3+) concentration on the fluorescence properties of Tm~(3+) ions is investigated by adjusting the Yb~(3+) concentration in Tm~(3+)/Yb~(3+):LaF_3 nanoparticles.It is found that for fluorescence emission at 474 nm,when the concentration of the Yb~(3+) increases,the fluorescence intensity also increases due to inverse energy transfer process.But the fluorescence intensity will decrease after it reaches a certain value.For the fluorescence emission at 450 nm,its intensity does not change obviously with the concentration of Yb~(3+) ions,but its fluorescence intensity is increasing firstly and then decrease like 474 nm fluorescence.