用水热法合成了NaYW2O8∶Ln3+(Ln=Yb/Er and Eu)微米晶,并研究了pH值对微米晶组成、形貌和荧光性质的影响。通过调节微米晶的形貌和结构对微米晶的上转换荧光进行了调控。在NaYW2O8∶Eu3+微米晶的激发光谱中,Eu3+-O2电荷迁移带和W6+-O2...用水热法合成了NaYW2O8∶Ln3+(Ln=Yb/Er and Eu)微米晶,并研究了pH值对微米晶组成、形貌和荧光性质的影响。通过调节微米晶的形貌和结构对微米晶的上转换荧光进行了调控。在NaYW2O8∶Eu3+微米晶的激发光谱中,Eu3+-O2电荷迁移带和W6+-O2-跃迁与Eu3+离子的f-f激发峰的比值随着微米晶的形貌和结构的不同发生改变。展开更多
The Sr2 CeO4:Ln3+(Ln=Eu,Dy)fine phosphor particles were prepared by a facile wet chemical approach,in which the consecutive hydrothermal-combustion reaction was performed.The doping of Ln3+into Sr2 CeO4 has little inf...The Sr2 CeO4:Ln3+(Ln=Eu,Dy)fine phosphor particles were prepared by a facile wet chemical approach,in which the consecutive hydrothermal-combustion reaction was performed.The doping of Ln3+into Sr2 CeO4 has little influence on the structure of host,and the as-prepared samples display wellcrystallized spherical or elliptical shape with an average particle size at about 100-200 nm.For Eu3+ions-doped Sr2 CeO4,with the increase of Eu3+-doping concentration,the blue light emission band with the maximum at 468 nm originating from a Ce4+→O2-charge transfer of the host decreases obviously and the characteristic red light emission of Eu3+(5 D0→7 F2 transition at 618 nm)is enhanced gradually.Simultaneously,the fluorescent lifetime of the broadband emission of Sr2 CeO4 decreases with the doping of Eu3+,indicating an efficient energy transfer from the host to the doping Eu3+ions.The ene rgy transfer efficiency from the host to Eu3+was investigated in detail,and the emitting color of Sr2 CeO4:Eu3+can be easily tuned from blue to red by varying the doping concentration of Eu3+ions.Moreover,the luminescence of Dy3+-doped Sr2 CeO4 was also studied.Similar energy transfer pheno menon can be observed,and the incorporation of Dy3+into Sr2 CeO4 host leads to the characteristic emission of 4 F9/2→6 H15/2(488 nm,blue light)and 4 F9/2→6 H13/2(574 nm,yellow light)of Dy3+.The Sr2 CeO4:Ln3+fine particles with tunable luminescence are quite beneficial for its potential applications in the optoelectronic fields.展开更多
Fluoride nanoparticles of Ln3＋（Ln3＋=Pr3＋, Nd3＋, Sm3＋, Cod3＋,Tb3＋ Dy3＋, I-I03＋, Er3＋, Tm3＋, yb3＋）/Eu3＋：LaOF and Eu3＋：LaOF with rhombohedral crystal structure were prepared by a hydrothermal-sintering ...Fluoride nanoparticles of Ln3＋（Ln3＋=Pr3＋, Nd3＋, Sm3＋, Cod3＋,Tb3＋ Dy3＋, I-I03＋, Er3＋, Tm3＋, yb3＋）/Eu3＋：LaOF and Eu3＋：LaOF with rhombohedral crystal structure were prepared by a hydrothermal-sintering method. The red fluorescence emission of Eu3＋ ions was found to be enhanced with most of the co-dopant Ln3. ions. Compared with strong fluorescence emission at 610 nm of Eu3＋：LaOF nanoparticles, the enhancement factors was up to ten times in Ln3~ （Ln3＋=Gd3＋, Dy3＋, Tm3＋）FEu3＋：LaOF co-doped nanoparticles. The results show that the asymmetry of the local environment of Eu3＋ ion was reduced by co-doping Ln3＋ ion into the nanoparticles, and that energy transfer might occur between Eu3_ and codopant Ln3＋ ions, which is suggested as the source of the observed fluorescence enhancement.展开更多
Zirconium metal-organic frameworks ZrOBDC(where BDC=C6H4(COOH)2,terephthalic acid)doped and co-doped with rare earth ions Ln(ZrOBDC:Ln^3+,where Ln^3+=Eu3+and Tb^3+as well as Er^3+and Yb^3+)were used as precursors for ...Zirconium metal-organic frameworks ZrOBDC(where BDC=C6H4(COOH)2,terephthalic acid)doped and co-doped with rare earth ions Ln(ZrOBDC:Ln^3+,where Ln^3+=Eu3+and Tb^3+as well as Er^3+and Yb^3+)were used as precursors for the design of tetragonal rare earth doped zirconia nanoparticles(t-ZrO2:Ln^3+NPs)through annealing process.Preparation,characterization and luminescence properties of ZrOBDC:Ln^3+and ZrO2:Ln^3+NPs were investigated.The as-obtained t-ZrO2:Ln^3+NPs have high purity with an average size of 20-30 nm.The luminescence spectra of ZrOBDC:Tb^3+and ZrOBDC:Eu3+display strong green and red emission at around 544 and 611 nm which correspond to 5D4→7F5 and 5D0→7F2 transitions of Tb^3+and Eu3+ions,respectively.The green and red up-conversion emissions of ZrO2:Er^3+,Yb^3+NPs due to 2H11/2,4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of the Er^3+ions are observed under 976 nm laser excitation.展开更多
文摘用水热法合成了NaYW2O8∶Ln3+(Ln=Yb/Er and Eu)微米晶,并研究了pH值对微米晶组成、形貌和荧光性质的影响。通过调节微米晶的形貌和结构对微米晶的上转换荧光进行了调控。在NaYW2O8∶Eu3+微米晶的激发光谱中,Eu3+-O2电荷迁移带和W6+-O2-跃迁与Eu3+离子的f-f激发峰的比值随着微米晶的形貌和结构的不同发生改变。
基金Project supported by National Natural Science Foundation of China(51972097)This work was financially supported by the Science Foundation of Hebei Normal University,China(L2019K11).This work was also financially supported by the project WINLEDS—POCI-01-0145-FEDER-030351 and developed within the scope of the project CICECO-Aveiro Institute of Materials,FCT Ref.UID/CTM/50011/2019,financed by national funds through the FCT/MCTES.
文摘The Sr2 CeO4:Ln3+(Ln=Eu,Dy)fine phosphor particles were prepared by a facile wet chemical approach,in which the consecutive hydrothermal-combustion reaction was performed.The doping of Ln3+into Sr2 CeO4 has little influence on the structure of host,and the as-prepared samples display wellcrystallized spherical or elliptical shape with an average particle size at about 100-200 nm.For Eu3+ions-doped Sr2 CeO4,with the increase of Eu3+-doping concentration,the blue light emission band with the maximum at 468 nm originating from a Ce4+→O2-charge transfer of the host decreases obviously and the characteristic red light emission of Eu3+(5 D0→7 F2 transition at 618 nm)is enhanced gradually.Simultaneously,the fluorescent lifetime of the broadband emission of Sr2 CeO4 decreases with the doping of Eu3+,indicating an efficient energy transfer from the host to the doping Eu3+ions.The ene rgy transfer efficiency from the host to Eu3+was investigated in detail,and the emitting color of Sr2 CeO4:Eu3+can be easily tuned from blue to red by varying the doping concentration of Eu3+ions.Moreover,the luminescence of Dy3+-doped Sr2 CeO4 was also studied.Similar energy transfer pheno menon can be observed,and the incorporation of Dy3+into Sr2 CeO4 host leads to the characteristic emission of 4 F9/2→6 H15/2(488 nm,blue light)and 4 F9/2→6 H13/2(574 nm,yellow light)of Dy3+.The Sr2 CeO4:Ln3+fine particles with tunable luminescence are quite beneficial for its potential applications in the optoelectronic fields.
基金supported by the National Natural Science Foundation of China (Grant No. 11174190)the Fundamental Research Funds for the Central Universities (Grant No. GK201101006)+1 种基金Shaanxi Normal University, the Natural Science Foundation (Grant No. NZ11252)the Key Technologies R&D Program (Grant No.08222-19) of Ningxia Province,China
文摘Fluoride nanoparticles of Ln3＋（Ln3＋=Pr3＋, Nd3＋, Sm3＋, Cod3＋,Tb3＋ Dy3＋, I-I03＋, Er3＋, Tm3＋, yb3＋）/Eu3＋：LaOF and Eu3＋：LaOF with rhombohedral crystal structure were prepared by a hydrothermal-sintering method. The red fluorescence emission of Eu3＋ ions was found to be enhanced with most of the co-dopant Ln3. ions. Compared with strong fluorescence emission at 610 nm of Eu3＋：LaOF nanoparticles, the enhancement factors was up to ten times in Ln3~ （Ln3＋=Gd3＋, Dy3＋, Tm3＋）FEu3＋：LaOF co-doped nanoparticles. The results show that the asymmetry of the local environment of Eu3＋ ion was reduced by co-doping Ln3＋ ion into the nanoparticles, and that energy transfer might occur between Eu3_ and codopant Ln3＋ ions, which is suggested as the source of the observed fluorescence enhancement.
基金Project supported by Vietnam National Foundation for Science and Technology Development(NAFOSTED,103.03-2016.60)the project collaborated between Polish Academy of Sciences and Vietnam Academy of Sciences and Technology(QTPL01.01/18-19)
文摘Zirconium metal-organic frameworks ZrOBDC(where BDC=C6H4(COOH)2,terephthalic acid)doped and co-doped with rare earth ions Ln(ZrOBDC:Ln^3+,where Ln^3+=Eu3+and Tb^3+as well as Er^3+and Yb^3+)were used as precursors for the design of tetragonal rare earth doped zirconia nanoparticles(t-ZrO2:Ln^3+NPs)through annealing process.Preparation,characterization and luminescence properties of ZrOBDC:Ln^3+and ZrO2:Ln^3+NPs were investigated.The as-obtained t-ZrO2:Ln^3+NPs have high purity with an average size of 20-30 nm.The luminescence spectra of ZrOBDC:Tb^3+and ZrOBDC:Eu3+display strong green and red emission at around 544 and 611 nm which correspond to 5D4→7F5 and 5D0→7F2 transitions of Tb^3+and Eu3+ions,respectively.The green and red up-conversion emissions of ZrO2:Er^3+,Yb^3+NPs due to 2H11/2,4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of the Er^3+ions are observed under 976 nm laser excitation.
