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Series of NaBa 0.97 Ce 0.03 B 9 O 15 : x Tb3+, y Sm3+, z Dy3+ are synthesized by the traditional high temperature solid-state method. Ce3+ is used as a sensitizer to improve the spectral properties of Tb3+, Sm3+ and Dy3+ by the way of energy transfer which is proved by the fluorescence decay curves. And the mechanisms of energy transfer from Ce3+ to Tb3+, Sm3+ and Dy3+ are all determined as dipole-dipole interaction. The color of NBB:3%Ce3+, x Tb3+, 0.5%Sm3+ can shift from light violet thought white to yellow. And NBB:3%Ce3+, z Dy3+ can give out white light and move to green field. Moreover, the thermal stability makes NBB:3%Ce3+, 0.2%Dy3+ be a potential candidate for the self-referencing luminescent thermometry. Image 1 [ABSTRACT FROM AUTHOR]

A series of color-tunable NaBa1−zSrzB9O15:Ce3+,Mn2+ phosphors were synthesized by a high temperature solid state method. Luminescence property, energy transfer, thermal stability and cation substitution were investigated in detail. Due to energy transfer, NaBaB9O15:Ce3+,Mn2+ presents violet to green luminescence and manifest a broad excitation range from 200 to 350 nm. The energy transfer mechanism of Ce3+–Mn2+ is identified as a dipole–dipole interaction. NaBa1−zSrzB9O15:Ce3+,Mn2+ displays both Ce3+ violet and Mn2+ green and orange emissions under ultraviolet excitation. It is observed that Sr2+ partial substitution for Ba2+ could adjust the ratio of Mn2+ emission intensity in different cation sites, which results from preferred sites’ occupation with modification of the crystal structure. Furthermore, increase in temperature can enhance the energy transfer from Ce3+ to Mn2+, which enhances the Mn2+ emission intensity sharply. The highly thermal-sensitive property of NaBa1−zSrzB9O15:Ce3+,Mn2+ makes it feasible for its potential application in luminescent ratiometric thermometers with wide temperature range. [ABSTRACT FROM AUTHOR]

A series of color-tunable NaBa1−zSrzB9O15:Ce3+,Mn2+ phosphors were synthesized by a high temperature solid state method. Luminescence property, energy transfer, thermal stability and cation substitution were investigated in detail. Due to energy transfer, NaBaB9O15:Ce3+,Mn2+ presents violet to green luminescence and manifest a broad excitation range from 200 to 350 nm. The energy transfer mechanism of Ce3+–Mn2+ is identified as a dipole–dipole interaction. NaBa1−zSrzB9O15:Ce3+,Mn2+ displays both Ce3+ violet and Mn2+ green and orange emissions under ultraviolet excitation. It is observed that Sr2+ partial substitution for Ba2+ could adjust the ratio of Mn2+ emission intensity in different cation sites, which results from preferred sites’ occupation with modification of the crystal structure. Furthermore, increase in temperature can enhance the energy transfer from Ce3+ to Mn2+, which enhances the Mn2+ emission intensity sharply. The highly thermal-sensitive property of NaBa1−zSrzB9O15:Ce3+,Mn2+ makes it feasible for its potential application in luminescent ratiometric thermometers with wide temperature range. [ABSTRACT FROM AUTHOR]

A series of Na 1-z K z Ba 1-y Sr y B 9 O 15 :Eu2+ were synthesized by the high temperature solid state method. H 3 BO 3 excess makes it easier for Eu2+ to enter Na+ site, and the single-phase "blue + green" double emission band can be observed, which is proved by thermoluminescence and the change of crystal structure. Moreover, there exists an intense energy transfer from the blue-emitting center to the green-emitting center, which is proved by the decay curve. The occupation of Eu2+ can be tuned by the introduction of Sr2+ and K+ in NaBaB 9 O 15. Further, the highly thermal-sensitive property of NaBaB 9 O 15 : 1%Eu2+ makes it feasible for its potential application in luminescent ratiometric thermometers with wide temperature range. In addition, the disorder degree of matrix cations increases with the incorporation of K+, which improves the thermal stability. Image 1 • Eu2+ can enter into Na+ site with the excessive H 3 BO 3 and muti-band emission is achieved. • Sr2+/K+ can adjust the occupied radio of Eu2+ in Ba2+ and Na+ site. • K+ can improve the thermal stability of NBB:Eu2+ due to the disorder degree of matrix cations. • NBB:1%Eu2+ could be a versatile solid-state probe. [ABSTRACT FROM AUTHOR]

Abstract Series of Ce3+/Eu2+, Ce3+/Mn2+ and Ce3+/Eu2+/Mn2+ doped Ba 3 Y(PO 4) 3 samples were synthesized by a high temperature solid state reaction method. Phase formation, energy transfer, luminescence properties and thermal quenching properties were investigated carefully. The energy transfer from Ce3+ to Eu2+ and Ce3+ to Mn2+ in Ba 3 Y(PO 4) 3 were verified and discussed detailed. When Ce3+ and Eu2+ are co-doped, the energy transfer process from Ce3+ to Eu2+ is confirmed with electric dipole-dipole interaction. For Ce3+/Mn2+ co-doped phosphors, the energy transfer process from Ce3+ to Mn2+ is proved with electric dipole-dipole interaction. Besides, due to the existence of defects, the phosphors show excellent thermal stability. For Ce3+/Eu2+/Mn2+ tri-doped Ba 3 Y(PO 4) 3 , the energy transfer Ce3+→Eu2+ (Mn2+) and Eu2+→Mn2+ are confirmed. The energy transfer priority among Ce3+, Eu2+ and Mn2+ is analyzed in detail basing on the change of emission intensity. The obtained tri-doped phosphors contain red, green and blue component, thus they can emit warm white light basing on the energy transfer. The results show that they may be novel white-light-emitting phosphors for ultraviolet white light emitting diodes. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Series of Sr 6 Ca 4 (PO 4) 6 F 2 :Ce3+, Tb3+, Sm3+ are prepared by a high temperature solid state method. Ce3+, Tb3+ or Sm3+ single-doped Sr 6 Ca 4 (PO 4) 6 F 2 can produce blue, green and red emission under ultraviolet excitation, respectively. However, the emission intensities of Tb3+ and Sm3+ are relatively weak due to their forbidden transition. In order to achieve white light, the spectral property and decay curves of Sr 6 Ca 4 (PO 4) 6 F 2 :Ce3+/Tb3+/Sm3+ are measured, not only the energy transfer of Ce3+-Tb3+, Ce3+-Sm3+ and Tb3+-Sm3+ was demonstrated, importantly, but also the single-phase white emitting phosphor Sr 6 Ca 4 (PO 4) 6 F 2 :0.14Ce3+, 0.07Tb3+,0.13Sm3+ was obtained by the energy transfer. [ABSTRACT FROM AUTHOR]