In this study,Er^(3+)/Yb^(3+)codoped Y_(2)O_(3)-ZnO ceramic phosphors were prepared by sol-gel method.The samples had two emission bands,namely,green(535 nm) and red(660 nm),which are attributed to Er^(3+):^(2)H_(11/2...In this study,Er^(3+)/Yb^(3+)codoped Y_(2)O_(3)-ZnO ceramic phosphors were prepared by sol-gel method.The samples had two emission bands,namely,green(535 nm) and red(660 nm),which are attributed to Er^(3+):^(2)H_(11/2)(^(4)S_(3/2))→^(4)I_(15/2)and Er^(3+):^(4)F_(9/2)→^(4)I_(15/2)radiative transitions,respectively.The samples exhibited green-and red-emission intensity enhancement by 1.728 and 2.286 times that of the pure Y2O3host,respectively and by 514.468 and 214.341 times that of the pure ZnO host.The emission intensities are first enhanced by lattice expansion.With the change of Y:Zn ratio,the high surface energy is converted into low crystal surface resulting in the change of asymmetry crystal field for matrix.When the intensity of the asymmetric crystal field reaches maximum,both emissions are further boosted.When the high surface energy transforms into crystal surface energy,the microstructure changes into a compact mesoporous structure.Consequently,the chemical stability of the samples improves significantly,and the final emission band of the three samples with mesoporous structures is continuously red.展开更多
Ultrafine-grained Al_(2)O_(3)–rare earth:yttrium aluminium garnet(Al_(2)O_(3)–RE:YAG)(RE=Ce;Ce+Gd)composite ceramics were obtained for the first time by reactive spark plasma sintering(SPS)using commercially availab...Ultrafine-grained Al_(2)O_(3)–rare earth:yttrium aluminium garnet(Al_(2)O_(3)–RE:YAG)(RE=Ce;Ce+Gd)composite ceramics were obtained for the first time by reactive spark plasma sintering(SPS)using commercially available initial oxide powders.The effect of key sintering parameters(temperature,dwell time,and external pressure(P_(load)))on densification peculiarities,structural-phase states,and luminescent properties of composites was studied comprehensively.Differences in phase formation and densification between Ce-doped and Ce,Gd-codoped systems were shown.Parameters of reactive SPS,at which there is partial melting with the formation of near-eutectic zones of the Al_(2)O_(3)–YAG system/coexistence of several variations of the YAG-type phase,were established.Pure corundum–garnet biphasic ceramics with an optimal balance between microstructural and luminescence performance were synthesized at 1425℃/30 min/30–60 MPa.The external quantum efficiency(EQE)of the phosphor converters reached 80.7%and 72%with close lifetime of~63.8 ns,similar to those of commercial Ce:YAG materials,which is promising for further applications in the field of high-power white light-emitting diodes(WLEDs)and laser diodes(LDs).展开更多
As the fourth-generation light source,solid-state lighting has developed rapidly in the past 30 years due to its advantages of high efficiency and environmental protection.It is widely used in various scenes such as a...As the fourth-generation light source,solid-state lighting has developed rapidly in the past 30 years due to its advantages of high efficiency and environmental protection.It is widely used in various scenes such as automobile headlights,projection displays,industrial production,and remote lighting.High-power,high-brightness white light-emitting diodes(LEDs)and laser diodes(LDs)technology put forward new requirements for the service stability of color conversion materials.Garnet phosphor ceramics have emerged with their unique advantages of withstanding high power excitation density and the flexibly tunable spectrum.In this article,the research progress of garnet based phosphor ceramics for high-power solid-state lighting was comprehensively reviewed.Firstly,the band gap and coordination environment regulations of luminescence centers of garnet phosphor were summarized.Secondly,the improvement of luminous efficacy via defects regulation was discussed.Thirdly,the relationship between the geometric design and the lighting performance was elucidated.Fourthly,the characterization methods of phosphor ceramics for laser lighting were introduced and illustrated.Finally,the development trend of garnet phosphor ceramics in solid state lighting and display was prospected.展开更多
A series of spinel-type Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)(MgAlON:xMn^(2+))phosphors were synthesized by the solid-state reaction route.The transparent ceramic phosphors were fabricated by pressureless sint...A series of spinel-type Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)(MgAlON:xMn^(2+))phosphors were synthesized by the solid-state reaction route.The transparent ceramic phosphors were fabricated by pressureless sintering followed by hot-isostatic pressing(HIP).The crystal structure,luminescence and mechanical properties of the samples were systematically investigated.The transparent ceramic phosphors with tetrahedrally coordinated Mn^(2+)show strong green emission centered around 515 nm under blue light excitation.As the Mn^(2+)concentration increases,the crystal lattice expands slightly,resulting in a variation of crystal field and a slight red-shift of green emission peak.Six weak absorption peaks in the transmittance spectra originate from the spin-forbidden ^(4)T_(1)(^(4)G)→^(6)A_(1) transition of Mn^(2+).The decay time was found to decrease from 5.66 to 5.16 ms with the Mn^(2+)concentration.The present study contributes to the systematic understanding of crystal structure and properties of MgAlON:xMn^(2+)green-emitting transparent ceramic phosphor which has a potential application in high-power light-emitting diodes.展开更多
The coexistence of pores in composite phosphor ceramics(CPCs)for solid-state lighting is not necessarily a disadvantage,and it may be more conducive to enhancing luminous efficiency.In this work,x wt%BaAl_(2)O_(4)-LuA...The coexistence of pores in composite phosphor ceramics(CPCs)for solid-state lighting is not necessarily a disadvantage,and it may be more conducive to enhancing luminous efficiency.In this work,x wt%BaAl_(2)O_(4)-LuAG:Ce CPCs(x=1,3,5,10)were fabricated via a solid-state reaction,which involves the coexistence of pores.BaAl_(2)O_(4) can not only function as a sintering aid but also form secondary phases serving as scattering centers.The 3 wt%BaAl_(2)O_(4)-LuAG:Ce exhibits an intriguing microstructure,where large and small grains of LuAG:Ce coexist alongside pores and secondary phases,demonstrating better luminescent properties.Under 0.92 W laser excitation at 450 nm,3 wt%BaAl_(2)O_(4)-LuAG:Ce exhibits an optimum luminous efficiency of 237 lm/W and a luminous flux of 218 lm.When the laser power reached 4.3 W,3 wt%BaAl_(2)O_(4)-LuAG:Ce exhibited an optimal luminous flux of 1015 lm,which shows the potential for application in solid-state lighting(SSL).展开更多
The utilization of blue lasers to excite phosphor materials holds great potential for the development of high-brightness laser-driven light sources.However,phosphor materials that can simultaneously constrain light sp...The utilization of blue lasers to excite phosphor materials holds great potential for the development of high-brightness laser-driven light sources.However,phosphor materials that can simultaneously constrain light spot expansion and enhance the maximum luminous flux have been elusive,thereby limiting the output luminance.In this study,optical fiber-inspired core–cladding phosphor ceramics(CCPC)of YAG:Ce@Al_(2)O_(3)wafers were engineered using a gel–casting technique to restrict light spot expansion.The smaller refractive index of Al_(2)O_(3),combined with the dense and sharp core–cladding interface of these CCPC,effectively confines the light spot area.The sample with a 1.0 mm core diameter has a small spot size nearly identical to that of the incident blue laser beam.Furthermore,the high thermal conductivity of the non-luminescent Al_(2)O_(3)cladding endows the CCPC with an impressive luminance saturation threshold of 30 W·mm^(-2)and a maximum luminous flux of 2100 lm for white light within a straightforward transmissive optical setup.The combination of a confined light-spot area and elevated luminous flux results in an ultra-high luminance of 3900 lm·mm^(-2),surpassing current reports.This research presents a pioneering approach to the design of phosphor materials,targeting the realization of light sources with unprecedented luminance for broad frontier applications.展开更多
In this study,deep-red emitting Mg2T i04:Mn4 phosphor ceramics were synthesized by the high temperature solid-state reaction method.The ceramics can be excited by the 465 nm blue light and had a narrow emission with a...In this study,deep-red emitting Mg2T i04:Mn4 phosphor ceramics were synthesized by the high temperature solid-state reaction method.The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum(FWMH)value of 31 nm.The peak wavelength was located at 658 nm,which matched the demanded wavelength for photosynthesis.The crystal field strength(Dq)and the Racah parameters(B and C)were estimated by the Tanabe-Sugano diagram.The thermal conductivity of the Mg2Ti(0.999)O4:0.001Mn^(4+)ceramic was 7.535 W/(m·K)at room temperature,which was one order of magnitude higher than that of the traditional packaging method using the silicone gel.A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue region to the purple light region with the thickness of the ceramic increasing.These results indicated that the Mg2Ti04:Mn^(4+)phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.展开更多
Near-infrared(NIR)phosphor-converted light-emitting diodes/laser diodes(LEDs/LDs)are prospective lighting sources for NIR spectroscopy.However,developing NIR phosphor materials with desired thermal robustness and high...Near-infrared(NIR)phosphor-converted light-emitting diodes/laser diodes(LEDs/LDs)are prospective lighting sources for NIR spectroscopy.However,developing NIR phosphor materials with desired thermal robustness and high photoelectric efficiency is a crucial challenge for their applications.In this work,based on the cationic radius matching effect,a series of(Lu,Y)_(3)(Al,Sc,Cr)_(2)Al_(3)O_(12)NIR phosphor ceramics(LuYScCr NIR-PCs)were fabricated by vacuum sintering.Excellent thermal stability(95%@150℃)was obtained in the prepared NIR-PCs,owing to their weak electron-phonon coupling effect(small Huang-Rhys factor).Being excited at 460 nm,NIR-PCs realized a broadband emission(650-850 nm)with internal quantum efficiency(IQE)of 60.68%.Combining NIR-PCs with LED/LD chips,the maximum output power of the encapsulated LED prototype was 447 mW@300 mA with photoelectric efficiency of as high as 18.6%@180 mA,and the maximum output power of the LD prototype was 814 mW@2.5 A.The working temperatures of NIR-PCs were 70.8℃@300 mA(LED)and 102.8℃@3 A(LD).Finally,the prepared NIR-PCs applied in food detection were verified in this study,demonstrating their anticipated application prospects in the future.展开更多
Achieving a high color rendering index(CRI)and luminous stability in single-structured Ce:Y_(3)Al_(5)O_(12)(Ce:YAG)phosphor ceramics(PCs)is crucial for high-power white light-emitting diodes or laser diodes(LEDs/LDs)....Achieving a high color rendering index(CRI)and luminous stability in single-structured Ce:Y_(3)Al_(5)O_(12)(Ce:YAG)phosphor ceramics(PCs)is crucial for high-power white light-emitting diodes or laser diodes(LEDs/LDs).However,cyan valleys and insufficient amounts of the red component in the Ce:YAG emission spectra significantly limit their real applications.In this work,a series of Ce,Mn:Y_(3)(Al,Sc)_(2)Al_(3)O_(12)(Ce,Mn:YSAG)PCs were fabricated by vacuum sintering,and efficient spectral regulation was realized for full-color lighting.The cyan valley was filled by the blueshifted emission peak of Ce^(3+)via Sc^(3+)doping.The orange‒red emission at approximately 580 nm was effectively supplemented via Mn^(2+)doping.In particular,CRI of Ce,Mn:YSAG increased from 56.4 to 85.8,a 52%increase compared with that of Ce:YAG under high-power LED excitation,and the operating temperature was stable at approximately 50℃for long working time.Moreover,CRI of 80.9 could still be obtained for PC-based white LDs.These results indicated that Ce,Mn:YSAG PC,which has excellent CRI and luminous stability,is an extremely promising color convertor for high-power white LEDs/LDs.展开更多
基金Project supported by the National Natural Science Foundation of China (12104117)Guangdong Basic and Applied Basic Research Foundation (2020A1515010432)Characteristic Innovation Project of Guangdong Provincial Universities 2020 (2020KTXCX077)。
文摘In this study,Er^(3+)/Yb^(3+)codoped Y_(2)O_(3)-ZnO ceramic phosphors were prepared by sol-gel method.The samples had two emission bands,namely,green(535 nm) and red(660 nm),which are attributed to Er^(3+):^(2)H_(11/2)(^(4)S_(3/2))→^(4)I_(15/2)and Er^(3+):^(4)F_(9/2)→^(4)I_(15/2)radiative transitions,respectively.The samples exhibited green-and red-emission intensity enhancement by 1.728 and 2.286 times that of the pure Y2O3host,respectively and by 514.468 and 214.341 times that of the pure ZnO host.The emission intensities are first enhanced by lattice expansion.With the change of Y:Zn ratio,the high surface energy is converted into low crystal surface resulting in the change of asymmetry crystal field for matrix.When the intensity of the asymmetric crystal field reaches maximum,both emissions are further boosted.When the high surface energy transforms into crystal surface energy,the microstructure changes into a compact mesoporous structure.Consequently,the chemical stability of the samples improves significantly,and the final emission band of the three samples with mesoporous structures is continuously red.
基金supported by the Russian Science Foundation(No.20-73-10242)Also,this work was partially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA22010301)+3 种基金the International Partnership Program of Chinese Academy of Sciences(No.121631KYSB20200039)the International Cooperation Project of Shanghai Science and Technology Commission(No.20520750200)Denis Yu.Kosyanov is grateful to the Council on grants of the President of the Russian Federation(No.SP-3221.2022.1)for supporting the studies devoted to obtaining advanced ceramic materialsThe SR XRD measurements were done at the shared research center SSTRC on the basis of the VEPP-4-VEPP-2000 complex at the Budker Institute of Nuclear Physics SB RAS.
文摘Ultrafine-grained Al_(2)O_(3)–rare earth:yttrium aluminium garnet(Al_(2)O_(3)–RE:YAG)(RE=Ce;Ce+Gd)composite ceramics were obtained for the first time by reactive spark plasma sintering(SPS)using commercially available initial oxide powders.The effect of key sintering parameters(temperature,dwell time,and external pressure(P_(load)))on densification peculiarities,structural-phase states,and luminescent properties of composites was studied comprehensively.Differences in phase formation and densification between Ce-doped and Ce,Gd-codoped systems were shown.Parameters of reactive SPS,at which there is partial melting with the formation of near-eutectic zones of the Al_(2)O_(3)–YAG system/coexistence of several variations of the YAG-type phase,were established.Pure corundum–garnet biphasic ceramics with an optimal balance between microstructural and luminescence performance were synthesized at 1425℃/30 min/30–60 MPa.The external quantum efficiency(EQE)of the phosphor converters reached 80.7%and 72%with close lifetime of~63.8 ns,similar to those of commercial Ce:YAG materials,which is promising for further applications in the field of high-power white light-emitting diodes(WLEDs)and laser diodes(LDs).
基金This work was financially supported from the National Key Re-search and Development Program of China(No.2021YFB3501700)the National Natural Science Foundation of China(Nos.52202135,61975070,51902143 and 61971207)+7 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Key Research and Development Project of Jiangsu Province(Nos.BE2021040 and BE2019033)the Natural Science Foundation of Jiangsu Province(Nos.BK20191467 and BK20221226)the Postgrad-uate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_2568)the International S&T Cooperation Program of Jiangsu Province(Nos.BZ2019063,BZ2020045 and BZ2020030)the Natural Science Foundation of the Jiangsu Higher Education In-stitutes of China(Nos.19KJB430018 and 20KJA430003)the Special Project for Technology Innovation of Xuzhou City(Nos.KC19250,KC20201,KC20244 and KC21379)Open Project of State Key Laboratory of Advanced Materials and Electronic Components(No.FHR-JS-202011017).The authors would like to show great appreci-ation to Prof.Ole Bjarlin Jensen from the Technical University of Denmark for his long-term support and guidance on diode laser-related knowledge and technique.
文摘As the fourth-generation light source,solid-state lighting has developed rapidly in the past 30 years due to its advantages of high efficiency and environmental protection.It is widely used in various scenes such as automobile headlights,projection displays,industrial production,and remote lighting.High-power,high-brightness white light-emitting diodes(LEDs)and laser diodes(LDs)technology put forward new requirements for the service stability of color conversion materials.Garnet phosphor ceramics have emerged with their unique advantages of withstanding high power excitation density and the flexibly tunable spectrum.In this article,the research progress of garnet based phosphor ceramics for high-power solid-state lighting was comprehensively reviewed.Firstly,the band gap and coordination environment regulations of luminescence centers of garnet phosphor were summarized.Secondly,the improvement of luminous efficacy via defects regulation was discussed.Thirdly,the relationship between the geometric design and the lighting performance was elucidated.Fourthly,the characterization methods of phosphor ceramics for laser lighting were introduced and illustrated.Finally,the development trend of garnet phosphor ceramics in solid state lighting and display was prospected.
基金Funded by the National Natural Science Foundation of China(No.52272072)the Independent Innovation Projects of the Hubei Longzhong Laboratory(No.2022ZZ-13)。
文摘A series of spinel-type Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)(MgAlON:xMn^(2+))phosphors were synthesized by the solid-state reaction route.The transparent ceramic phosphors were fabricated by pressureless sintering followed by hot-isostatic pressing(HIP).The crystal structure,luminescence and mechanical properties of the samples were systematically investigated.The transparent ceramic phosphors with tetrahedrally coordinated Mn^(2+)show strong green emission centered around 515 nm under blue light excitation.As the Mn^(2+)concentration increases,the crystal lattice expands slightly,resulting in a variation of crystal field and a slight red-shift of green emission peak.Six weak absorption peaks in the transmittance spectra originate from the spin-forbidden ^(4)T_(1)(^(4)G)→^(6)A_(1) transition of Mn^(2+).The decay time was found to decrease from 5.66 to 5.16 ms with the Mn^(2+)concentration.The present study contributes to the systematic understanding of crystal structure and properties of MgAlON:xMn^(2+)green-emitting transparent ceramic phosphor which has a potential application in high-power light-emitting diodes.
基金supported by the National Key R&D Program of China(Grant No.2023YFB3506600)the International Partnership Program of the Chinese Academy of Sciences(Grant No.121631KYSB20200039)the Natural Science Foundation of Shanghai(Grant No.22ZR1472100).
文摘The coexistence of pores in composite phosphor ceramics(CPCs)for solid-state lighting is not necessarily a disadvantage,and it may be more conducive to enhancing luminous efficiency.In this work,x wt%BaAl_(2)O_(4)-LuAG:Ce CPCs(x=1,3,5,10)were fabricated via a solid-state reaction,which involves the coexistence of pores.BaAl_(2)O_(4) can not only function as a sintering aid but also form secondary phases serving as scattering centers.The 3 wt%BaAl_(2)O_(4)-LuAG:Ce exhibits an intriguing microstructure,where large and small grains of LuAG:Ce coexist alongside pores and secondary phases,demonstrating better luminescent properties.Under 0.92 W laser excitation at 450 nm,3 wt%BaAl_(2)O_(4)-LuAG:Ce exhibits an optimum luminous efficiency of 237 lm/W and a luminous flux of 218 lm.When the laser power reached 4.3 W,3 wt%BaAl_(2)O_(4)-LuAG:Ce exhibited an optimal luminous flux of 1015 lm,which shows the potential for application in solid-state lighting(SSL).
基金supported by the National Key R&D Program of China(MOSTNo.2022YFE0108800)+2 种基金the National Natural Science Foundation of China(No.52272165)the Fujian Provincial Natural Science Foundation of China(No.2024J09009)the Xiamen Major Science and Technology Project(No.3502Z20231050).
文摘The utilization of blue lasers to excite phosphor materials holds great potential for the development of high-brightness laser-driven light sources.However,phosphor materials that can simultaneously constrain light spot expansion and enhance the maximum luminous flux have been elusive,thereby limiting the output luminance.In this study,optical fiber-inspired core–cladding phosphor ceramics(CCPC)of YAG:Ce@Al_(2)O_(3)wafers were engineered using a gel–casting technique to restrict light spot expansion.The smaller refractive index of Al_(2)O_(3),combined with the dense and sharp core–cladding interface of these CCPC,effectively confines the light spot area.The sample with a 1.0 mm core diameter has a small spot size nearly identical to that of the incident blue laser beam.Furthermore,the high thermal conductivity of the non-luminescent Al_(2)O_(3)cladding endows the CCPC with an impressive luminance saturation threshold of 30 W·mm^(-2)and a maximum luminous flux of 2100 lm for white light within a straightforward transmissive optical setup.The combination of a confined light-spot area and elevated luminous flux results in an ultra-high luminance of 3900 lm·mm^(-2),surpassing current reports.This research presents a pioneering approach to the design of phosphor materials,targeting the realization of light sources with unprecedented luminance for broad frontier applications.
基金Shanghai Pujiang Program(18PJ1408800)Shanghai Science and Technology Innovation Program(19511104600)+1 种基金the National Key Research and Development Program of China(2016YFB1102303)the International Partnership Program of Chinese Academy of Sciences(181231KYSB20160005).
文摘In this study,deep-red emitting Mg2T i04:Mn4 phosphor ceramics were synthesized by the high temperature solid-state reaction method.The ceramics can be excited by the 465 nm blue light and had a narrow emission with a full width at half maximum(FWMH)value of 31 nm.The peak wavelength was located at 658 nm,which matched the demanded wavelength for photosynthesis.The crystal field strength(Dq)and the Racah parameters(B and C)were estimated by the Tanabe-Sugano diagram.The thermal conductivity of the Mg2Ti(0.999)O4:0.001Mn^(4+)ceramic was 7.535 W/(m·K)at room temperature,which was one order of magnitude higher than that of the traditional packaging method using the silicone gel.A set of phosphor converted LEDs were fabricated by mounting the phosphor ceramics onto the 460 nm blue LED chips and the CIE coordinates can move from the blue region to the purple light region with the thickness of the ceramic increasing.These results indicated that the Mg2Ti04:Mn^(4+)phosphor ceramic was suitable for plant lighting when combined with a blue LED chip.
基金The authors acknowledge the generous financial support from the National Natural Science Foundation of China(Nos.52302139,61973103,52272141,and 51972060)Doctoral Foundation Project of Henan University of Technology(No.2021BS069)+3 种基金Natural Science Foundation of Henan Province Youth Fund(No.222300420039)the Key Science and Technology Program of Henan Province(Nos.222102210023 and 232102211074)Project of Songshan Laboratory(No.YYJC072022020)Key Specialized Research of Zhengzhou Science and Technology Innovation Cooperation(No.21ZZXTCX01).
文摘Near-infrared(NIR)phosphor-converted light-emitting diodes/laser diodes(LEDs/LDs)are prospective lighting sources for NIR spectroscopy.However,developing NIR phosphor materials with desired thermal robustness and high photoelectric efficiency is a crucial challenge for their applications.In this work,based on the cationic radius matching effect,a series of(Lu,Y)_(3)(Al,Sc,Cr)_(2)Al_(3)O_(12)NIR phosphor ceramics(LuYScCr NIR-PCs)were fabricated by vacuum sintering.Excellent thermal stability(95%@150℃)was obtained in the prepared NIR-PCs,owing to their weak electron-phonon coupling effect(small Huang-Rhys factor).Being excited at 460 nm,NIR-PCs realized a broadband emission(650-850 nm)with internal quantum efficiency(IQE)of 60.68%.Combining NIR-PCs with LED/LD chips,the maximum output power of the encapsulated LED prototype was 447 mW@300 mA with photoelectric efficiency of as high as 18.6%@180 mA,and the maximum output power of the LD prototype was 814 mW@2.5 A.The working temperatures of NIR-PCs were 70.8℃@300 mA(LED)and 102.8℃@3 A(LD).Finally,the prepared NIR-PCs applied in food detection were verified in this study,demonstrating their anticipated application prospects in the future.
基金financially supported by the National Key R&D Program of China(No.2021YFB3501700)the National Natural Science Foundation of China(Nos.52202135,61975070,and 52302141)+4 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),the International S&T Cooperation Program of Jiangsu Province(No.BZ2023007)the Key R&D Project of Jiangsu Province(Nos.BE2023050 and BE2021040)Natural Science Foundation of Jiangsu Province(No.BK20221226)the Special Project for Technology Innovation of Xuzhou City(Nos.KC23380,KC21379,KC22461,and KC22497)the Open Project of State Key Laboratory of Crystal Materials(No.KF2205).
文摘Achieving a high color rendering index(CRI)and luminous stability in single-structured Ce:Y_(3)Al_(5)O_(12)(Ce:YAG)phosphor ceramics(PCs)is crucial for high-power white light-emitting diodes or laser diodes(LEDs/LDs).However,cyan valleys and insufficient amounts of the red component in the Ce:YAG emission spectra significantly limit their real applications.In this work,a series of Ce,Mn:Y_(3)(Al,Sc)_(2)Al_(3)O_(12)(Ce,Mn:YSAG)PCs were fabricated by vacuum sintering,and efficient spectral regulation was realized for full-color lighting.The cyan valley was filled by the blueshifted emission peak of Ce^(3+)via Sc^(3+)doping.The orange‒red emission at approximately 580 nm was effectively supplemented via Mn^(2+)doping.In particular,CRI of Ce,Mn:YSAG increased from 56.4 to 85.8,a 52%increase compared with that of Ce:YAG under high-power LED excitation,and the operating temperature was stable at approximately 50℃for long working time.Moreover,CRI of 80.9 could still be obtained for PC-based white LDs.These results indicated that Ce,Mn:YSAG PC,which has excellent CRI and luminous stability,is an extremely promising color convertor for high-power white LEDs/LDs.
