Tb3＋-doped Ca2BO3C1 compounds with different charge compensation approaches are synthesized by a hightemperature solid-state reaction method, and the luminescent properties and Commission Internationale de l＇Eclaira...Tb3＋-doped Ca2BO3C1 compounds with different charge compensation approaches are synthesized by a hightemperature solid-state reaction method, and the luminescent properties and Commission Internationale de l＇Eclairage （CIE） chromaticity coordinates are systematically characterized. Ca2BO3Cl：Tb3＋ can produce green emission under 376 nm radiation excitation. With codoped A＋ （A = Li, Na, K） as charge compensators, the relative emission intensities of Ca2BO3Cl：Tb3＋ are enhanced by about 1.61, 1.97, and 1.81 times compared with those of the direct charge balance, which is considered to be due to the effect of the difference in ion radius on the crystal field. The CIE chromaticity coordinates of Ca2BO3CI：Tb3＋, A＋ （A = Li, Na, K） are （0.335, 0.584）, （0.335, 0.585）, and （0.335, 0.585）, corresponding to the hues of green. Therefore, A＋ （A = Li, Na, K） may be the optimal charge compensator for Ca2BO3Cl：Tb3＋.展开更多
Energy transfer is a promising strategy to improve the visible light emitting efficiency of phosphors. A series of Ce3＋, Tb3＋, Dy3＋ and/or EU3＋ doped Na3Y（BO3）2 （NYB） were prepared by solid-state reaction and ...Energy transfer is a promising strategy to improve the visible light emitting efficiency of phosphors. A series of Ce3＋, Tb3＋, Dy3＋ and/or EU3＋ doped Na3Y（BO3）2 （NYB） were prepared by solid-state reaction and their photoluminescence properties were studied in detail. The excitation and emission spectra of NYB：Ce3＋,Tb3＋ and NYB：Ce3＋,Dy3＋ revealed that an efficient energy transfer process from Ce3＋ to Zb3＋ or Dy3＋ occurred upon excitation Ce3＋ into 5d level. The dependence of the decay times of Ce3＋ 5d level on Tb3＋ or Dy3＋ concentration indicated that the energy transfer efficiency increased with increasing Tb3＋ or Dy3＋ content. So the UV excitation light could be converted into green or near-white emission. However, there was no obvious evidence of the existence of energy transfer from Ce3＋ to Eu3＋ in NYB.展开更多
The phase diagram of system Na<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub>-H<sub>2</sub>O has been investigated by many authors. The left part （Al<sub>2</sub>O...The phase diagram of system Na<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub>-H<sub>2</sub>O has been investigated by many authors. The left part （Al<sub>2</sub>O<sub>3</sub>·3H<sub>2</sub>O as solid phase） of the diagram of Na<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub>-H<sub>2</sub>O system is of no problem, but the right part （hydrated sodium aluminates as solid phases） is in controversies. Jucaitis concluded that there were two hydrated sodium aluminates, i.e. Na<sub>2</sub>O·Al<sub>2</sub>O<sub>3</sub>·2.5H<sub>2</sub>O and 3Na<sub>2</sub>O·Al<sub>2</sub>O<sub>3</sub>·6H<sub>2</sub>O. Kuznetsov suspected the existence of the latter and believed that it was actually a mixture of Na<sub>2</sub>O·Al<sub>2</sub>O<sub>3</sub>·2.5H<sub>2</sub>O展开更多
基金supported by the National Basic Research Program of China(Grant No.2010CB327704)the National Natural Science Foundation of China(Grant No.51272022)+3 种基金the New Century Excellent Talents in University,China(Grant No.NCET-10-0220)the Research Fund for the Doctoral Program of Higher Education,China(Grant No.20120009130005)the Excellent Doctor's Science and Technology Innovation Foundation of Beijing Jiaotong University,China(Grant No.2011YJS073)the Fundamental Research Funds for the Central Universities(Grant No.2012JBZ001)
文摘Tb3＋-doped Ca2BO3C1 compounds with different charge compensation approaches are synthesized by a hightemperature solid-state reaction method, and the luminescent properties and Commission Internationale de l＇Eclairage （CIE） chromaticity coordinates are systematically characterized. Ca2BO3Cl：Tb3＋ can produce green emission under 376 nm radiation excitation. With codoped A＋ （A = Li, Na, K） as charge compensators, the relative emission intensities of Ca2BO3Cl：Tb3＋ are enhanced by about 1.61, 1.97, and 1.81 times compared with those of the direct charge balance, which is considered to be due to the effect of the difference in ion radius on the crystal field. The CIE chromaticity coordinates of Ca2BO3CI：Tb3＋, A＋ （A = Li, Na, K） are （0.335, 0.584）, （0.335, 0.585）, and （0.335, 0.585）, corresponding to the hues of green. Therefore, A＋ （A = Li, Na, K） may be the optimal charge compensator for Ca2BO3Cl：Tb3＋.
基金Project supported by the National Natural Science Foundation of China(11274038)
文摘Energy transfer is a promising strategy to improve the visible light emitting efficiency of phosphors. A series of Ce3＋, Tb3＋, Dy3＋ and/or EU3＋ doped Na3Y（BO3）2 （NYB） were prepared by solid-state reaction and their photoluminescence properties were studied in detail. The excitation and emission spectra of NYB：Ce3＋,Tb3＋ and NYB：Ce3＋,Dy3＋ revealed that an efficient energy transfer process from Ce3＋ to Zb3＋ or Dy3＋ occurred upon excitation Ce3＋ into 5d level. The dependence of the decay times of Ce3＋ 5d level on Tb3＋ or Dy3＋ concentration indicated that the energy transfer efficiency increased with increasing Tb3＋ or Dy3＋ content. So the UV excitation light could be converted into green or near-white emission. However, there was no obvious evidence of the existence of energy transfer from Ce3＋ to Eu3＋ in NYB.
文摘The phase diagram of system Na<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub>-H<sub>2</sub>O has been investigated by many authors. The left part （Al<sub>2</sub>O<sub>3</sub>·3H<sub>2</sub>O as solid phase） of the diagram of Na<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub>-H<sub>2</sub>O system is of no problem, but the right part （hydrated sodium aluminates as solid phases） is in controversies. Jucaitis concluded that there were two hydrated sodium aluminates, i.e. Na<sub>2</sub>O·Al<sub>2</sub>O<sub>3</sub>·2.5H<sub>2</sub>O and 3Na<sub>2</sub>O·Al<sub>2</sub>O<sub>3</sub>·6H<sub>2</sub>O. Kuznetsov suspected the existence of the latter and believed that it was actually a mixture of Na<sub>2</sub>O·Al<sub>2</sub>O<sub>3</sub>·2.5H<sub>2</sub>O
