The red, green and blue （R/G/B） tricolor emitting phosphors Ba2ZnSi2O7 co-doped with Ce3＋and Eu3＋were synthesized in air atmosphere by a conventional high temperature solid-state reaction technique. All of the exc...The red, green and blue （R/G/B） tricolor emitting phosphors Ba2ZnSi2O7 co-doped with Ce3＋and Eu3＋were synthesized in air atmosphere by a conventional high temperature solid-state reaction technique. All of the excitation spectrum of the phosphor Ba2ZnSi2O7：Ce,Eu showed a strong broad band absorption in the n-UV region whenever monitored by red （630 nm）-emitting or by green （500 nm）-and blue （402 nm）-emitting. Under the excitation of 330 nm, the emission spectrum containing a blue-violet emis-sion band, a green emission and four sharp lines originated from the characteristic transitions of Ce3＋, Eu2＋and Eu3＋ions, of which the relative intensities of the three emission bands could be controlled by the doping concentration of Ce3＋. The ca. CIE chromaticity co-ordinates （x=0.317, y=0.309） of the phosphor Ba1.94ZnSi2O7：0.03Eu,0.01Ce was very close to the standard white （x=0.33, y=0.33）, which suggested that it was a novel single-phased white-light emitting phosphor for LED-based near-UV chip. The mechanisms of energy transfer from Eu2＋to Eu3＋via Ce3＋was also discussed.展开更多
Red phosphors, Li2Sr0.996 Si O4： Pr3＋0.004, with different hydrothermal conditions were prepared via hydrothermal synthesis and then heat-treatment. The chemical structures of the phosphors were identified with X-ra...Red phosphors, Li2Sr0.996 Si O4： Pr3＋0.004, with different hydrothermal conditions were prepared via hydrothermal synthesis and then heat-treatment. The chemical structures of the phosphors were identified with X-ray diffraction（XRD）. Surface morphological features were observed by scanning electron microscopic（SEM） investigation. Spectra of excitation and emission for the phosphors were also obtained by a spectrophotometer. Results showed that the optimum conditions were as follows： p H value of solution was 1–2, reaction temperature was at 180 oC for 24 h. The as-prepared phosphors exhibited two excitation dominant peaks at 451 and 486 nm, attributed to transitions of 3H4→3P2 and 3H4→3P0 of Pr3＋, respectively. A narrow emission peak at 610 nm corresponded to the energy level transition of 3P0→3H6 of Pr3＋ under excitation of light at 451 nm, which indicated promising candidate red phosphors for blue LED chips.展开更多
A series of high phase purity blue light excitable yellow-emitting LaSiN:xCephosphors were synthesized by the high temperature solid state reactions method. The structure and luminescent properties were investigated. ...A series of high phase purity blue light excitable yellow-emitting LaSiN:xCephosphors were synthesized by the high temperature solid state reactions method. The structure and luminescent properties were investigated. The phase structure was studied by means of X-ray diffraction, structures refinements and energy dispersive X-ray spectroscopy. The phosphors effectively excited by the light of450 nm and show intense yellow emission at 535 nm with FWHM of 115 nm corresponding to the5 d →~2 Fand 5 d →~2 Ftransitions of Ce. In addition,the optimized LaSiN:0.14 Ceexhibits a weak thermal quenching, which remains 98.2% of the initial emission intensity when heated to 200 ℃,the thermal quenching properties exhibit a modest decline when the temperature returned to room temperature. The above results indicate that LaSiN:Cecan be regarded as a high promising phosphor for applications in high power white-light LED.展开更多
基金Project supported by the National Natural Science Foundation of China(20971042)Specialized Research Fund for the Doctoral Program of Higher Education(20124306120005,20134306120009)+2 种基金Hunan Provincial Natural Science Foundation of China(2015JJ2100)Scientific Research Fund of Hunan Provincial Education Department(13C012)Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
文摘The red, green and blue （R/G/B） tricolor emitting phosphors Ba2ZnSi2O7 co-doped with Ce3＋and Eu3＋were synthesized in air atmosphere by a conventional high temperature solid-state reaction technique. All of the excitation spectrum of the phosphor Ba2ZnSi2O7：Ce,Eu showed a strong broad band absorption in the n-UV region whenever monitored by red （630 nm）-emitting or by green （500 nm）-and blue （402 nm）-emitting. Under the excitation of 330 nm, the emission spectrum containing a blue-violet emis-sion band, a green emission and four sharp lines originated from the characteristic transitions of Ce3＋, Eu2＋and Eu3＋ions, of which the relative intensities of the three emission bands could be controlled by the doping concentration of Ce3＋. The ca. CIE chromaticity co-ordinates （x=0.317, y=0.309） of the phosphor Ba1.94ZnSi2O7：0.03Eu,0.01Ce was very close to the standard white （x=0.33, y=0.33）, which suggested that it was a novel single-phased white-light emitting phosphor for LED-based near-UV chip. The mechanisms of energy transfer from Eu2＋to Eu3＋via Ce3＋was also discussed.
基金Project supported by the Fujian Provincial Key Project(2013H6020)
文摘Red phosphors, Li2Sr0.996 Si O4： Pr3＋0.004, with different hydrothermal conditions were prepared via hydrothermal synthesis and then heat-treatment. The chemical structures of the phosphors were identified with X-ray diffraction（XRD）. Surface morphological features were observed by scanning electron microscopic（SEM） investigation. Spectra of excitation and emission for the phosphors were also obtained by a spectrophotometer. Results showed that the optimum conditions were as follows： p H value of solution was 1–2, reaction temperature was at 180 oC for 24 h. The as-prepared phosphors exhibited two excitation dominant peaks at 451 and 486 nm, attributed to transitions of 3H4→3P2 and 3H4→3P0 of Pr3＋, respectively. A narrow emission peak at 610 nm corresponded to the energy level transition of 3P0→3H6 of Pr3＋ under excitation of light at 451 nm, which indicated promising candidate red phosphors for blue LED chips.
基金Project supported by the National Basic Research Program of China(2014CB643801)
文摘A series of high phase purity blue light excitable yellow-emitting LaSiN:xCephosphors were synthesized by the high temperature solid state reactions method. The structure and luminescent properties were investigated. The phase structure was studied by means of X-ray diffraction, structures refinements and energy dispersive X-ray spectroscopy. The phosphors effectively excited by the light of450 nm and show intense yellow emission at 535 nm with FWHM of 115 nm corresponding to the5 d →~2 Fand 5 d →~2 Ftransitions of Ce. In addition,the optimized LaSiN:0.14 Ceexhibits a weak thermal quenching, which remains 98.2% of the initial emission intensity when heated to 200 ℃,the thermal quenching properties exhibit a modest decline when the temperature returned to room temperature. The above results indicate that LaSiN:Cecan be regarded as a high promising phosphor for applications in high power white-light LED.
