1 Introduction Sodium borates as important raw materials are widely used in the field of glass industry,ceramic industry,medical industry,paper industry,agriculture and so on for
Rare earth(RE) pentaborates,both α-and β-polymorphs,are good candidates for photoluminescent hosts suitable for various RE activators,Ce^(3+) acts not only as an activator itself,but also as a sensitizer to other ra...Rare earth(RE) pentaborates,both α-and β-polymorphs,are good candidates for photoluminescent hosts suitable for various RE activators,Ce^(3+) acts not only as an activator itself,but also as a sensitizer to other rare earth activators,like in the case of commercial green phosphor CeMgAl_(11)O_(19):Tb^(3+).In this work,two solid solutions of β-La_(0.9-x)Ce_(0.1)Tb_(x)B_(5)O_(9)(0≤x≤0.15) and β-La_(0.9-y)Ce_(0.1)Dy_(y)B_(5)O_(9)(0≤y≤0.07)were prepared by sol-gel method with high crystallinity,and the phase purity was confirmed with careful analyses on powder X-ray diffraction patterns.Energy transfers are expected due to the overlapping of Ce^(3+)emission with the Tb^(3+)/Dy^(3+)excitation.Indeed,the steady photoluminescence spectra indicate the decrease of the Ce^(3+)emission and the increase of the Tb^(3+)/Dy^(3+) emission,and the fluorescence decay curves exhibit the decrease of the average lifetime of Ce^(3+).The energy transfer efficiency is estimated to be 60% at χ=0.15 and 55% at y=0.07,respectively.The mechanism is likely through the dipole-dipole electric interactions for both cases.With this rationale,the Tb^(3+)and Dy^(3+)emissions are greatly enhanced,in particular,the white emission of Dy^(3+)in β-La_(0.85)Ce_(0.1)Dy_(0.05)B_(5)O_(9) is enhanced by 20 times.展开更多
基金Financial supports from the NNSFCs (Grants 21276194 and 21306136)the Specialized Research Fund for the Doctoral Program of Chinese Higher Education (Grant 20101208110003)the Opening Funds of Tianjin Key Laboratory of Marine Resources and Chemistry for Tianjin University of Science and Technology (Grant 201206)
文摘1 Introduction Sodium borates as important raw materials are widely used in the field of glass industry,ceramic industry,medical industry,paper industry,agriculture and so on for
基金Project supported by the National Natural Science Foundation of China (21771027,21671028,21805020)Natural Science Foundation of Chongqing (cstc2019jcyj-msxmX0330)。
文摘Rare earth(RE) pentaborates,both α-and β-polymorphs,are good candidates for photoluminescent hosts suitable for various RE activators,Ce^(3+) acts not only as an activator itself,but also as a sensitizer to other rare earth activators,like in the case of commercial green phosphor CeMgAl_(11)O_(19):Tb^(3+).In this work,two solid solutions of β-La_(0.9-x)Ce_(0.1)Tb_(x)B_(5)O_(9)(0≤x≤0.15) and β-La_(0.9-y)Ce_(0.1)Dy_(y)B_(5)O_(9)(0≤y≤0.07)were prepared by sol-gel method with high crystallinity,and the phase purity was confirmed with careful analyses on powder X-ray diffraction patterns.Energy transfers are expected due to the overlapping of Ce^(3+)emission with the Tb^(3+)/Dy^(3+)excitation.Indeed,the steady photoluminescence spectra indicate the decrease of the Ce^(3+)emission and the increase of the Tb^(3+)/Dy^(3+) emission,and the fluorescence decay curves exhibit the decrease of the average lifetime of Ce^(3+).The energy transfer efficiency is estimated to be 60% at χ=0.15 and 55% at y=0.07,respectively.The mechanism is likely through the dipole-dipole electric interactions for both cases.With this rationale,the Tb^(3+)and Dy^(3+)emissions are greatly enhanced,in particular,the white emission of Dy^(3+)in β-La_(0.85)Ce_(0.1)Dy_(0.05)B_(5)O_(9) is enhanced by 20 times.
