A series of K3Gd1-x-y(PO4)2:xCe^3+, yTb^3+ phosphors are synthesized by the solid-sate reaction method. X-ray diffraction and photoluminescence spectra are utilized to characterize the structures and luminescence...A series of K3Gd1-x-y(PO4)2:xCe^3+, yTb^3+ phosphors are synthesized by the solid-sate reaction method. X-ray diffraction and photoluminescence spectra are utilized to characterize the structures and luminescence properties of the as-synthesized phosphors. Co-doping of Ce^3+ enhances the emission intensity of Tb^3+ greatly through an efficient energy transfer process from Ce^3+ to Tb^3+. The energy transfer is confirmed by photoluminescence spectra and decay time curves analysis. The efficiency and mechanism of energy transfer are investigated carefully. Moreover, due to the non- concentration quenching property of K3Tb(PO4)2, the photoluminescence spectra of K3Tb1-x(PO4)2:xCe^3+ are studied and the results show that when x = 0.11 the strongest Tb^3+ green emission can be realized.展开更多
A novel red-emitting phosphor, CaYA1307: Eu^3+, Sm^3+, is synthesized by a combustion method at a low temperature (850 ℃), and the single phase of CaYA1307 is confirmed by powder X-ray diffraction measurements. ...A novel red-emitting phosphor, CaYA1307: Eu^3+, Sm^3+, is synthesized by a combustion method at a low temperature (850 ℃), and the single phase of CaYA1307 is confirmed by powder X-ray diffraction measurements. The photoluminescence property results reveal that the red emission intensity of Eu^3+ is strongly dependent on the Sm^3+ concentration. Only the Eu^3+ luminescence is detected in the Eu^3+-Sm^3+ co-doped CaYA1307 phosphor with 393 nm excitation. However, under the characteristic excitation (402 nm) of Sm^3+, not only the Sm^3+ emission but also the Eu^3+ emission are observed. A possible mechanism of the energy transfer between Sm^3+ and Eu3+ is investigated in detail.展开更多
KaGd(PO4)2:Tb3+ phosphors are synthesized by the solid reaction method, and the phases and lu- minescence properties of the obtained phosphors are well characterized. The emission spectra of KaGd(PO4)2:Tb3+ ex...KaGd(PO4)2:Tb3+ phosphors are synthesized by the solid reaction method, and the phases and lu- minescence properties of the obtained phosphors are well characterized. The emission spectra of KaGd(PO4)2:Tb3+ exhibit the typical emissions of Tb3+. Concentration quenching of Tb3+ is not observed in KaGd(PO4)2:Tb3+, likely because the shortest average distance of Tb3+-Tb3+ in KaGd(POn)2:Tb3+ is adequately long such that energy transfer between Tb3+-Tb3+ ions cannot take place effectively. This re- sult indicates that KaTb(P04)2 phosphors have potential application in near ultraviolet (n-UV)-convertible phosphors for white light-emitting diodes.展开更多
A series of single-phased Ca2Al2SiOT:EU2+phosphors were synthesized by the solid-state reaction. Their structure and photoluminescence properties were investigated by the X-ray powder diffraction (XRD) and excitat...A series of single-phased Ca2Al2SiOT:EU2+phosphors were synthesized by the solid-state reaction. Their structure and photoluminescence properties were investigated by the X-ray powder diffraction (XRD) and excitation and emission spectra in detail. The emission spectra of Ca2Al2SiO7:Eu2+ phosphors consisted of blue and green band located at 419 and 542 nm, respectively. The relative intensities of the blue and green emission changed with Eu2+ concentration and were sensitive to the excitation wavelength. The unique photoluminescence property originated from the 4f^7→4f65d transition of Eu2+ at different energy levels, on which the effect of the crystal field strength was con- sidered to be tailed by adjusting the host composition.展开更多
Monovalent ions Li+, Na+, and K+, as charge compensators, are introduced into CaYA1307: M (M = Eu3+, Ce~+) in this letter. Their crystal phases and photoluminescence properties of different alkali metal ions d...Monovalent ions Li+, Na+, and K+, as charge compensators, are introduced into CaYA1307: M (M = Eu3+, Ce~+) in this letter. Their crystal phases and photoluminescence properties of different alkali metal ions doped in CaYA1307 are investigated. In addition, the influence of charge compensation ion Li+ which has a more obvious role in improving luminescence intensity on CaYA1307: Eu3+ phosphor is intentionally discussed in detail and a possible mechanism of charge compensation is given. The enhancement of red emission centered at 618 nm belonging to Eu3+ is achieved by adding alkali metal ion Li+ under 393-nm excitation.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11204113,61265004,and 51272097)the Foundation of Application Research of Yunnan Province,China (Grant No.2011FB022)+2 种基金the Chinese Specialized Research Fund for the Doctoral Program of Higher Education (Grant No.20115314120001)the Postdoctoral Science Foundation of China (Grant No.2011M501424)the National Basic Research Program of China (Grant No.2011CB211708)
文摘A series of K3Gd1-x-y(PO4)2:xCe^3+, yTb^3+ phosphors are synthesized by the solid-sate reaction method. X-ray diffraction and photoluminescence spectra are utilized to characterize the structures and luminescence properties of the as-synthesized phosphors. Co-doping of Ce^3+ enhances the emission intensity of Tb^3+ greatly through an efficient energy transfer process from Ce^3+ to Tb^3+. The energy transfer is confirmed by photoluminescence spectra and decay time curves analysis. The efficiency and mechanism of energy transfer are investigated carefully. Moreover, due to the non- concentration quenching property of K3Tb(PO4)2, the photoluminescence spectra of K3Tb1-x(PO4)2:xCe^3+ are studied and the results show that when x = 0.11 the strongest Tb^3+ green emission can be realized.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11204113, 61265004, and 51272097)the Foundation of Application Research of Yunnan Province, China (Grant No. 2011FB022)+2 种基金the Chinese Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20115314120001)the Postdoctoral Science Foundation of China (Grant No. 2011M501424)the National Basic Research Program of China (Grant No. 2011CB211708)
文摘A novel red-emitting phosphor, CaYA1307: Eu^3+, Sm^3+, is synthesized by a combustion method at a low temperature (850 ℃), and the single phase of CaYA1307 is confirmed by powder X-ray diffraction measurements. The photoluminescence property results reveal that the red emission intensity of Eu^3+ is strongly dependent on the Sm^3+ concentration. Only the Eu^3+ luminescence is detected in the Eu^3+-Sm^3+ co-doped CaYA1307 phosphor with 393 nm excitation. However, under the characteristic excitation (402 nm) of Sm^3+, not only the Sm^3+ emission but also the Eu^3+ emission are observed. A possible mechanism of the energy transfer between Sm^3+ and Eu3+ is investigated in detail.
基金supported by the National Natural Science Foundation of China(Nos.11204113,61265004,and 51272097)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20115314120001)the Foundation of Natural Science of Yunnan Province(No.2011FB022)
文摘KaGd(PO4)2:Tb3+ phosphors are synthesized by the solid reaction method, and the phases and lu- minescence properties of the obtained phosphors are well characterized. The emission spectra of KaGd(PO4)2:Tb3+ exhibit the typical emissions of Tb3+. Concentration quenching of Tb3+ is not observed in KaGd(PO4)2:Tb3+, likely because the shortest average distance of Tb3+-Tb3+ in KaGd(POn)2:Tb3+ is adequately long such that energy transfer between Tb3+-Tb3+ ions cannot take place effectively. This re- sult indicates that KaTb(P04)2 phosphors have potential application in near ultraviolet (n-UV)-convertible phosphors for white light-emitting diodes.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (20115314120001) the Special Program for National Program on Key Basic Research Project of China (973 Program) (2011CB211708) the Foundation of Natural Science of Yunnan Province (2011FB022)
文摘A series of single-phased Ca2Al2SiOT:EU2+phosphors were synthesized by the solid-state reaction. Their structure and photoluminescence properties were investigated by the X-ray powder diffraction (XRD) and excitation and emission spectra in detail. The emission spectra of Ca2Al2SiO7:Eu2+ phosphors consisted of blue and green band located at 419 and 542 nm, respectively. The relative intensities of the blue and green emission changed with Eu2+ concentration and were sensitive to the excitation wavelength. The unique photoluminescence property originated from the 4f^7→4f65d transition of Eu2+ at different energy levels, on which the effect of the crystal field strength was con- sidered to be tailed by adjusting the host composition.
基金supported by the National Natural Science Foundation of China(Nos.11204113,61265004,and 51272097)the Foundation of Application Research of Yunnan Province(No.2011FB022)+2 种基金the Chinese Specialized Research Fund for the Doctoral Program of Higher Education(No.20115314120001)the Postdoctoral Science Foundation of China(No.2011M501424)the Nature and Science Fund from Yunnan ProvinceMinistry of Education(No.2011C13211708)
文摘Monovalent ions Li+, Na+, and K+, as charge compensators, are introduced into CaYA1307: M (M = Eu3+, Ce~+) in this letter. Their crystal phases and photoluminescence properties of different alkali metal ions doped in CaYA1307 are investigated. In addition, the influence of charge compensation ion Li+ which has a more obvious role in improving luminescence intensity on CaYA1307: Eu3+ phosphor is intentionally discussed in detail and a possible mechanism of charge compensation is given. The enhancement of red emission centered at 618 nm belonging to Eu3+ is achieved by adding alkali metal ion Li+ under 393-nm excitation.