In order to obtain near-infrared phosphor pumped by blue chip with high luminous efficiency, a novel near-infrared phosphor Ce^(3+)/Er^(3+) doped La_3Si_6N_(11) was designed and firstly prepared via conventional solid...In order to obtain near-infrared phosphor pumped by blue chip with high luminous efficiency, a novel near-infrared phosphor Ce^(3+)/Er^(3+) doped La_3Si_6N_(11) was designed and firstly prepared via conventional solid-state reactions. The structure and morphology of Ce^(3+)/Er^(3+) doped La_3Si_6N_(11) were investigated by X-ray diffraction(XRD) and scanning electron microscopy(SEM). Compared with Er^(3+) doped La_3Si_6N_(11),the emission intensity of the Ce^(3+), Er^(3+) co-doped phosphor can be increased more than 5 times.Meanwhile, the mechanism of energy transfer from Ce^(3+) to Er^(3+) is confirmed according to the excitation,emission spectra and decay lifetimes curve. Above results suggest that La_3 Si_6 N_(11):Ce^(3+),Er^(3+) is a promising near-infrared phosphor for blue pumped LEDs(light-emitting diodes).展开更多
A series of Sm^(3+)-doped La_(3)Si_(6)N_(11)phosphor materials we re synthesized by a high temperature solid-state reaction method.The crystal structure,micro structure,photoluminescence properties,decay curves as wel...A series of Sm^(3+)-doped La_(3)Si_(6)N_(11)phosphor materials we re synthesized by a high temperature solid-state reaction method.The crystal structure,micro structure,photoluminescence properties,decay curves as well as thermal quenching properties of the as-prepared phosphors were investigated systematically.The excitation spectra contain a wide asymmetric band below 350 nm originating from the host absorption,several sharp excitation peaks in the range of 300-550 nm corresponding to f-f transition of Sm^(3+).Under the excitation of 369 and 414 nm light,the phosphors exhibit strong narrow-band orangered emission peaked at 605 nm.The average decay time of La_(2.99)Si_(6)N_(11):0.01 Sm^(3+)sample is fitted to be0.38 ms and the CIE coordinates were calculated to be(0.6105,0.3833).For water resistance,La_(3)Si_(6)N_(11):Sm^(3+)is better than K_(2)SiF_(6):Mn^(4+)phosphor.After soaking in deionized water for 300 min,the La_(3)Si_(6)N_(11):Sm^(3+)sample retains approximately 80%of its initial relative emission intensity.When the temperature rises to 423 K(150℃),the emission intensity of La_(2.99)Si_(6)N_(11):0.01 Sm^(3+)sample remains 85%in co mparison to that of room tempe rature.The activation energy was calculated to be 0.63253 eV,which is higher than those of Sm^(3+)-activated oxide phosphors,indicating that the phosphor has relatively good thermal stability.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 Key Strategic Advanced Electronic Materials Department of the Ministry of Science and Technology,(2017YFB0404300,2017YFB0404301)
文摘In order to obtain near-infrared phosphor pumped by blue chip with high luminous efficiency, a novel near-infrared phosphor Ce^(3+)/Er^(3+) doped La_3Si_6N_(11) was designed and firstly prepared via conventional solid-state reactions. The structure and morphology of Ce^(3+)/Er^(3+) doped La_3Si_6N_(11) were investigated by X-ray diffraction(XRD) and scanning electron microscopy(SEM). Compared with Er^(3+) doped La_3Si_6N_(11),the emission intensity of the Ce^(3+), Er^(3+) co-doped phosphor can be increased more than 5 times.Meanwhile, the mechanism of energy transfer from Ce^(3+) to Er^(3+) is confirmed according to the excitation,emission spectra and decay lifetimes curve. Above results suggest that La_3 Si_6 N_(11):Ce^(3+),Er^(3+) is a promising near-infrared phosphor for blue pumped LEDs(light-emitting diodes).
基金the Doctoral Scientific Research Foundation of Jiangxi University of Science and Technology(3401223311)Science and Technology Research Project of Jiangxi Provincial Education Department(GJJ160636)+1 种基金National Natural Science Foundation of China(51962005)Natural Science Foundation of Jiangxi Province of China(20192BAB206010)。
文摘A series of Sm^(3+)-doped La_(3)Si_(6)N_(11)phosphor materials we re synthesized by a high temperature solid-state reaction method.The crystal structure,micro structure,photoluminescence properties,decay curves as well as thermal quenching properties of the as-prepared phosphors were investigated systematically.The excitation spectra contain a wide asymmetric band below 350 nm originating from the host absorption,several sharp excitation peaks in the range of 300-550 nm corresponding to f-f transition of Sm^(3+).Under the excitation of 369 and 414 nm light,the phosphors exhibit strong narrow-band orangered emission peaked at 605 nm.The average decay time of La_(2.99)Si_(6)N_(11):0.01 Sm^(3+)sample is fitted to be0.38 ms and the CIE coordinates were calculated to be(0.6105,0.3833).For water resistance,La_(3)Si_(6)N_(11):Sm^(3+)is better than K_(2)SiF_(6):Mn^(4+)phosphor.After soaking in deionized water for 300 min,the La_(3)Si_(6)N_(11):Sm^(3+)sample retains approximately 80%of its initial relative emission intensity.When the temperature rises to 423 K(150℃),the emission intensity of La_(2.99)Si_(6)N_(11):0.01 Sm^(3+)sample remains 85%in co mparison to that of room tempe rature.The activation energy was calculated to be 0.63253 eV,which is higher than those of Sm^(3+)-activated oxide phosphors,indicating that the phosphor has relatively good thermal stability.
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.
