Mn^3＋ and Bi^3＋ co-doped Y6WO12 samples with hexagonal structure were synthesized via an improved salt pyrogenation method at a temperature region of 700-1100 ℃ for 3 h. In Y6WO12, Mn^3＋, substituting y^3＋, occup...Mn^3＋ and Bi^3＋ co-doped Y6WO12 samples with hexagonal structure were synthesized via an improved salt pyrogenation method at a temperature region of 700-1100 ℃ for 3 h. In Y6WO12, Mn^3＋, substituting y^3＋, occupies a seven-coordination site and its energy levels are treated in near Oh symmetry. The samples doped by Mn^3＋ alone emit the most intensive blue light at 420 nm under excitation at 247 nm due to charge transition （CT）. The mechanism of sensitization of Bi^3＋ for Y6WO12：Mn^3＋ was also analyzed by taking account of metal-to-metal chargetransfer （MMCT） from Bi^3＋ to Mn^3＋. As a consequence, the phosphor Y6WO12：Mn^3＋/Bi^3＋ can emit blue light under radiation of 370 nm, and the emission intensity is enhanced about five times by the sensitizer Bi^3＋. The optimal doping concentration of Bi^3＋ is determined as 1 at% for the emission at 420 nm in Y6WO12：0.5 at% Mn^3＋ phosphors.展开更多
Full-spectrum phosphor-converted white-light-emitting diodes(pc-WLED)are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a ...Full-spectrum phosphor-converted white-light-emitting diodes(pc-WLED)are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a 400 nm NUV diode chip is still lacking.Herein,we present a blue-emitting Na_(3)KMg_(7)(PO_(4))6:Eu^(2+)phosphor synthesized by the solid-reaction method.Particularly,we find that the using of Li_(2)CO_(3)as flux can significantly improve the crystal quality and thus the emission efficiency of the phosphor.Meanwhile,the excitation peak of the phosphor shifts from 365 to 400 nm,which is pivotal for efficient NUV(400 nm)diode chip excitation.The practical Eu^(2+)concentration is also enhanced by using Li_(2)CO_(3)as flux,and the absorption efficiency is greatly increased.This phosphor exhibits superior PL thermal stability,namely retains 94%integrated photoluminescence intensity at 150℃of that at 25℃.As a result,the optimized phosphor shows an emission band peaked at 437 nm with a bandwidth of 40 nm and a high external photoluminescence quantum yield of 51.7%.Finally,a pc-WLED was fabricated by using NKMPO:Eu^(2+)blue,Sr_(2)SiO_(4):Eu^(2+)green,CaAlSiN_(3):Eu^(2+)red phosphors,and a 400 nm NUV diode chip.It shows a high color rendering index of R_(a)=96.4 and a correlated color temperature of 4358 K.These results prove that NKMPO:Eu^(2+)is a promising blue phosphor for full-spectrum WLED based on NUV diode chips.展开更多
Van der Waals heterostructures composed of low-dimensional atomic layers host rich physics for new device applications,such as magic-angle twisted bilayer graphene and coaxial multi-walled hetero-nanotubes.Aside from ...Van der Waals heterostructures composed of low-dimensional atomic layers host rich physics for new device applications,such as magic-angle twisted bilayer graphene and coaxial multi-walled hetero-nanotubes.Aside from exploring their abnormal physical behavior,fabrication of such structures also presents a great challenge to this area,owing to the subtle and sensitive interactions among neighboring layers.Here we show by molecular dynamics simulations that narrow blue phosphorene nanoribbons can be encapsulated into carbon nanotubes driven by van der Waals interactions and form one-dimensional heterostructures.It shows that by varying carbon nanotube diameters and nanoribbon width,the nanoribbons can either retain their original straight structures or twist into tubular structures.Wrapping phases are also observed for large-sized blue phosphorus.It is found that the underlying mechanism originates from the competition between van der Waals energy and bending energy induced by tube curvature.A phase diagram of the resultant 1D structure is thus obtained based on a simple analysis of energetics.The results are expected to stimulate further experimental efforts in fabricating one-dimensional van der Waals heterostructues with desired functionality.展开更多
For exploring new and efficient luminescent materials,we developed an efficient narrow-band blue-emitting phosphor Eu^(2+)doped Na_(3)CsMg_(7)(PO_(4))_(6).Under near-ultraviolet light excitation,the phosphor can emit ...For exploring new and efficient luminescent materials,we developed an efficient narrow-band blue-emitting phosphor Eu^(2+)doped Na_(3)CsMg_(7)(PO_(4))_(6).Under near-ultraviolet light excitation,the phosphor can emit bright blue light with a narrow FWHM of about 53 nm peaked at 463 nm with a high quantum yield of about 88.1%.And it has a broad excitation spectrum from 250 nm to 435 nm,and the strongest absorption is located between 350 and 410 nm,which can be efficiently excited by near-ultraviolet LED chips.展开更多
By optimizing the Debye temperature,we identified two extremely efficient phosphors based on the S-P transition of Bi^(3+).The quantum yields of Sr_(0.99)Ga_(1.50)B_(2)O_(7):0.01Bi^(3+),0.50Al^(3+)and Ba_(0.995)Ga_(1....By optimizing the Debye temperature,we identified two extremely efficient phosphors based on the S-P transition of Bi^(3+).The quantum yields of Sr_(0.99)Ga_(1.50)B_(2)O_(7):0.01Bi^(3+),0.50Al^(3+)and Ba_(0.995)Ga_(1.60)B_(2)O_(7):0.005Bi^(3+),0.40Al^(3+)phosphors reach 96%and 99%,respectively.Moreover,Sr_(0.99)Ga_(1.50)B_(2)O_(7):0.01Bi^(3+),0.50Al^(3+)exhibits negative thermal quenching,which shows unique advantages for practical application.The blue phosphors with quantum efficiencies close to unity and superior thermal stability can be competitive candidates for practical applications.展开更多
With the pursuit of healthy lighting,full-spectrum white light-emitting diodes(WLEDs)fabricated with violet chips and tri-color phosphors have been put forward.However,the excitation bands of most reported blue phosph...With the pursuit of healthy lighting,full-spectrum white light-emitting diodes(WLEDs)fabricated with violet chips and tri-color phosphors have been put forward.However,the excitation bands of most reported blue phosphors are located in the ultraviolet(UV)region,which hinders the development of fullspectrum lighting.In this work.展开更多
A broadband blue-emitting Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+)(x=0-0.2) phospho rs were synthesized,which can be used for near-UV pumped white light-emitting diodes(w-LEDs).The crystal structures,photoluminescence pro pe...A broadband blue-emitting Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+)(x=0-0.2) phospho rs were synthesized,which can be used for near-UV pumped white light-emitting diodes(w-LEDs).The crystal structures,photoluminescence pro perties,external quantum efficiency,the rmal stability and application perfo rmance of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+),by partially substituting Sr^(2+) with Ca^(2+)(x=0-0.2),were studied by various analytical techniques.When the Ca/Sr ratio of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) gradually increases,the emission peak of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) red-shiftes from 459 to 465 nm,corrected external quantum efficiency increases from 31.8% to 42.9%,and the thermal stability is also improved.The mechanism of the changes of the photoluminescence emission and excitation spectra,external quantum efficiency and thermal stability properties was also investigated in detail.In addition,a w-LED was fabricated by using SrLu_(2)O_(4):Ce^(3+)(blue),β-sialon:Eu^(2+)(green) and(Sr,Ca)AlSiN_(3):Eu^(2+)(red) phosphors combined with a 405 nm near-UV LED chip,and its color rendering index(CRI) reaches 96.0.When Sr_(0.8)Ca_(0.2)Lu_(2)O_(4):Ce^(3+) is applied as blue phosphor to substitute SrLu_(2)O_(4):Ce^(3+),the obtained w-LED devices have high luminous efficiency,and CRI greater than 95.0.These re sults show that the Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) can be potential blue phosphors for n-UV pumped high CRI w-LEDs application.展开更多
Blue-violet light can not only enhance the total content of biomass and glucoside but also enrich the taste of the fruit.Thus,it is meaningful to study the blue-violet luminescent materials for plant cultivation.In th...Blue-violet light can not only enhance the total content of biomass and glucoside but also enrich the taste of the fruit.Thus,it is meaningful to study the blue-violet luminescent materials for plant cultivation.In this study,titanium(IV)-activated CaYAlO4(CYAO) phosphors were synthesized by conventional hightemperature solid-state reaction.X-ray powder diffraction was employed to analyze the crystalstructure of CYAO.It is found that the doped Ti^4+ ions do not change obviously the crystal structure of phosphors.Upon 246 nm excitation,CaYAl1-xO4:xTi^4+phosphors exhibit broad blue-violet emission band peaking at 395 nm,which can be attributed to the charge transfer of Ti^4+-O^2-.Moreover,this phosphor exhibits strong thermal stability.The luminescence emission intensity at 150℃maintained about 91 mol% of its initial value at room temperature.Additionally,the electron transition process and concentration quenching mechanism of CaYAl1-xO4:xTi^4+are discussed in detail.The excellent luminescent properties indicate that CaYAl1-xO4:xTi^4+phosphor may have promising application in indoor plant cultivation.展开更多
The Eu 2+ and Dy 3+ codoped Sr 2MgSi 2O 7: Eu 2+ ,Dy 3+ blue emission long afterglow phosphor was synthesized and its photoluminescence properties were studied. It is known with the measurement method of X ray diffrac...The Eu 2+ and Dy 3+ codoped Sr 2MgSi 2O 7: Eu 2+ ,Dy 3+ blue emission long afterglow phosphor was synthesized and its photoluminescence properties were studied. It is known with the measurement method of X ray diffraction pattern that the luminescent material is an akermanite crystal. It is shown with the decay curve that its afterglow properties are better than the traditional (Ca,Sr)S:Bi blue long afterglow phosphor. Its decay curve is in accordance with the calculated results of the formula lg I=A+B 1 ×lg t +B 2×(lg t ) 2. Ther moluminescence spectra identified the existence of long afterglow luminescence. The excitation and emission spectra and microstructure of the phosphor were also investigated in detail.展开更多
Fluorescence enhancement of red and blue concurrently emitting Ba3MgSi2O8:Eu2+,Mn2+ phosphors for plant cultivation has been investigated by Dy3+ addition.The Ba3MgSi2O8:Eu2+,Mn2+,Dy3+(BMS-EMD) phosphors have two-colo...Fluorescence enhancement of red and blue concurrently emitting Ba3MgSi2O8:Eu2+,Mn2+ phosphors for plant cultivation has been investigated by Dy3+ addition.The Ba3MgSi2O8:Eu2+,Mn2+,Dy3+(BMS-EMD) phosphors have two-color emissions at the wavelength peak values of 437 nm and 620 nm at the excitation of 350 nm.The two emission bands are coincident with the absorption spectrum for photosynthesis of plants.An obvious enhancement effect has been observed upon addition of Dy3+ with amount of 0.03 mol%,in which the ...展开更多
The color conversion glass ceramics which were made of borosilicate matrix co-doped(SrBaSm)Si2O2N2:(Eu^3+Ce^3+) blue-green phosphors were prepared by two-step method in co-sintering. The change in luminescence propert...The color conversion glass ceramics which were made of borosilicate matrix co-doped(SrBaSm)Si2O2N2:(Eu^3+Ce^3+) blue-green phosphors were prepared by two-step method in co-sintering. The change in luminescence properties and the drift of chromaticity coordinates(CIE) of the(SrBaSm)Si2O2N2:(Eu^3+Ce^3+) blue-green phosphors and the color conversion glass ceramics were studied in the sintering temperature range from 600℃ to 800℃. The luminous intensity and internal quantum yield(QY) of the blue-green phosphors and glass ceramics decreased with the sintering temperature increasing. When the sintering temperature increased beyond 750℃, the phosphors and the color conversion glass ceramics almost had no peak in photoluminescence(PL) and excitation(PLE) spectra. The results showed that the blue-green phosphors had poor thermal stability at higher temperature. The lattice structure of the phosphors was destroyed by the glass matrix and the Ce^3+ in the phosphors was oxidized to Ce^4+, which further caused a decrease in luminescent properties of the color conversion glass ceramics.展开更多
The blue-emitting phosphor is one of the trichromatic phosphors essential for the development of nearultraviolet(nUV)pumped phosphor-converted white light-emitting diodes(pc-WLEDs).Efficiency and thermal stability are...The blue-emitting phosphor is one of the trichromatic phosphors essential for the development of nearultraviolet(nUV)pumped phosphor-converted white light-emitting diodes(pc-WLEDs).Efficiency and thermal stability are two critical factors for the potential application of phosphors in solid-state lighting.In this work,we report a highly efficient blue-emitting phosphor.展开更多
In the process of developing high-performance LCDs,narrow-band emitting phosphors with excellent performance are indispensable.In this study,a narrow-band blue phosphor BaZnAl_(10)O_(17):Eu^(2+)with an emission peak a...In the process of developing high-performance LCDs,narrow-band emitting phosphors with excellent performance are indispensable.In this study,a narrow-band blue phosphor BaZnAl_(10)O_(17):Eu^(2+)with an emission peak at 433 nm(which can be excited by near-ultraviolet light)and a full width at half maximum of 46 nm was found.The synthesized BaZnAl_(10)O_(17):Eu^(2+)phosphor exhibits low thermal quenching behavior.There is only 16.4%loss in emission intensity at 423 K compared to the initial intensity at room temperature.Using the narrow-band emission phosphor BaZnAl_(10)O_(17):Eu^(2+)as the blue light source,the prepared white LED device excited using a near-ultraviolet chip emits high-brightness white light(CCT=4436 K,R_(a)=93.96),whose CIE coordinates are(0.3387,0.3785)and CG can reach 99%of the NTSC standard.The narrow-band blue-emitting BaZnAl_(10)O_(17):Eu^(2+)phosphor has potential application value in white light-emitting diodes.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51401130 and 51704064)Program for Liaoning Innovative Research Team in University (No. LT2015020)+2 种基金Hebei Province Higher Education Science and Technology Research Project (No. ZD2017309)Scientific and Technological Research and Development Plan of Qinhuangdao City (No. 201701B063)Northeastern University at Qinhuangdao Campus Research Fund (No. XNK201602)
文摘Mn^3＋ and Bi^3＋ co-doped Y6WO12 samples with hexagonal structure were synthesized via an improved salt pyrogenation method at a temperature region of 700-1100 ℃ for 3 h. In Y6WO12, Mn^3＋, substituting y^3＋, occupies a seven-coordination site and its energy levels are treated in near Oh symmetry. The samples doped by Mn^3＋ alone emit the most intensive blue light at 420 nm under excitation at 247 nm due to charge transition （CT）. The mechanism of sensitization of Bi^3＋ for Y6WO12：Mn^3＋ was also analyzed by taking account of metal-to-metal chargetransfer （MMCT） from Bi^3＋ to Mn^3＋. As a consequence, the phosphor Y6WO12：Mn^3＋/Bi^3＋ can emit blue light under radiation of 370 nm, and the emission intensity is enhanced about five times by the sensitizer Bi^3＋. The optimal doping concentration of Bi^3＋ is determined as 1 at% for the emission at 420 nm in Y6WO12：0.5 at% Mn^3＋ phosphors.
基金Project supported by the National Natural Science Foundation of China(11974351)。
文摘Full-spectrum phosphor-converted white-light-emitting diodes(pc-WLED)are emerging as a mainstream technology in semiconductor lighting.Nevertheless,high-performance blue phosphor which can be excited efficiently by a 400 nm NUV diode chip is still lacking.Herein,we present a blue-emitting Na_(3)KMg_(7)(PO_(4))6:Eu^(2+)phosphor synthesized by the solid-reaction method.Particularly,we find that the using of Li_(2)CO_(3)as flux can significantly improve the crystal quality and thus the emission efficiency of the phosphor.Meanwhile,the excitation peak of the phosphor shifts from 365 to 400 nm,which is pivotal for efficient NUV(400 nm)diode chip excitation.The practical Eu^(2+)concentration is also enhanced by using Li_(2)CO_(3)as flux,and the absorption efficiency is greatly increased.This phosphor exhibits superior PL thermal stability,namely retains 94%integrated photoluminescence intensity at 150℃of that at 25℃.As a result,the optimized phosphor shows an emission band peaked at 437 nm with a bandwidth of 40 nm and a high external photoluminescence quantum yield of 51.7%.Finally,a pc-WLED was fabricated by using NKMPO:Eu^(2+)blue,Sr_(2)SiO_(4):Eu^(2+)green,CaAlSiN_(3):Eu^(2+)red phosphors,and a 400 nm NUV diode chip.It shows a high color rendering index of R_(a)=96.4 and a correlated color temperature of 4358 K.These results prove that NKMPO:Eu^(2+)is a promising blue phosphor for full-spectrum WLED based on NUV diode chips.
基金supported by the National Natural Science Foundation of China via Grant Nos.12072134 and 22073048Jiangsu Province NSF via Grant No.BK20191426supported by Jiangsu Province Research Innovation Program Project for University Postgraduates (#KYCX21_3325).
文摘Van der Waals heterostructures composed of low-dimensional atomic layers host rich physics for new device applications,such as magic-angle twisted bilayer graphene and coaxial multi-walled hetero-nanotubes.Aside from exploring their abnormal physical behavior,fabrication of such structures also presents a great challenge to this area,owing to the subtle and sensitive interactions among neighboring layers.Here we show by molecular dynamics simulations that narrow blue phosphorene nanoribbons can be encapsulated into carbon nanotubes driven by van der Waals interactions and form one-dimensional heterostructures.It shows that by varying carbon nanotube diameters and nanoribbon width,the nanoribbons can either retain their original straight structures or twist into tubular structures.Wrapping phases are also observed for large-sized blue phosphorus.It is found that the underlying mechanism originates from the competition between van der Waals energy and bending energy induced by tube curvature.A phase diagram of the resultant 1D structure is thus obtained based on a simple analysis of energetics.The results are expected to stimulate further experimental efforts in fabricating one-dimensional van der Waals heterostructues with desired functionality.
基金funding support of the National Natural Science Foundations of China(No.51972152)and we also thank Prof.Yonggang Wang for his selfless help in the high-pressure photoluminescence property measurements.
文摘For exploring new and efficient luminescent materials,we developed an efficient narrow-band blue-emitting phosphor Eu^(2+)doped Na_(3)CsMg_(7)(PO_(4))_(6).Under near-ultraviolet light excitation,the phosphor can emit bright blue light with a narrow FWHM of about 53 nm peaked at 463 nm with a high quantum yield of about 88.1%.And it has a broad excitation spectrum from 250 nm to 435 nm,and the strongest absorption is located between 350 and 410 nm,which can be efficiently excited by near-ultraviolet LED chips.
基金supported by the Key Laboratory for Green Chemical Process of Ministry of Education,Wuhan Institute of Technology,via grant GCP20190201。
文摘By optimizing the Debye temperature,we identified two extremely efficient phosphors based on the S-P transition of Bi^(3+).The quantum yields of Sr_(0.99)Ga_(1.50)B_(2)O_(7):0.01Bi^(3+),0.50Al^(3+)and Ba_(0.995)Ga_(1.60)B_(2)O_(7):0.005Bi^(3+),0.40Al^(3+)phosphors reach 96%and 99%,respectively.Moreover,Sr_(0.99)Ga_(1.50)B_(2)O_(7):0.01Bi^(3+),0.50Al^(3+)exhibits negative thermal quenching,which shows unique advantages for practical application.The blue phosphors with quantum efficiencies close to unity and superior thermal stability can be competitive candidates for practical applications.
基金supported by the National Natural Science Foundation of China(No.51832005).
文摘With the pursuit of healthy lighting,full-spectrum white light-emitting diodes(WLEDs)fabricated with violet chips and tri-color phosphors have been put forward.However,the excitation bands of most reported blue phosphors are located in the ultraviolet(UV)region,which hinders the development of fullspectrum lighting.In this work.
基金Project supported by the National Key Research and Development Program of China(2017YFB0404301)。
文摘A broadband blue-emitting Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+)(x=0-0.2) phospho rs were synthesized,which can be used for near-UV pumped white light-emitting diodes(w-LEDs).The crystal structures,photoluminescence pro perties,external quantum efficiency,the rmal stability and application perfo rmance of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+),by partially substituting Sr^(2+) with Ca^(2+)(x=0-0.2),were studied by various analytical techniques.When the Ca/Sr ratio of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) gradually increases,the emission peak of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) red-shiftes from 459 to 465 nm,corrected external quantum efficiency increases from 31.8% to 42.9%,and the thermal stability is also improved.The mechanism of the changes of the photoluminescence emission and excitation spectra,external quantum efficiency and thermal stability properties was also investigated in detail.In addition,a w-LED was fabricated by using SrLu_(2)O_(4):Ce^(3+)(blue),β-sialon:Eu^(2+)(green) and(Sr,Ca)AlSiN_(3):Eu^(2+)(red) phosphors combined with a 405 nm near-UV LED chip,and its color rendering index(CRI) reaches 96.0.When Sr_(0.8)Ca_(0.2)Lu_(2)O_(4):Ce^(3+) is applied as blue phosphor to substitute SrLu_(2)O_(4):Ce^(3+),the obtained w-LED devices have high luminous efficiency,and CRI greater than 95.0.These re sults show that the Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) can be potential blue phosphors for n-UV pumped high CRI w-LEDs application.
基金supported by the National Natural Science Foundation of China(21706060,51703061)Natural Science Foundation of Hunan Province(2017JJ3103)+1 种基金Youth Project of Hunan Education Department(17B1118)Hunan Provincial Engineering Technology Research Center for Optical Agriculture(2018TP2003).
文摘Blue-violet light can not only enhance the total content of biomass and glucoside but also enrich the taste of the fruit.Thus,it is meaningful to study the blue-violet luminescent materials for plant cultivation.In this study,titanium(IV)-activated CaYAlO4(CYAO) phosphors were synthesized by conventional hightemperature solid-state reaction.X-ray powder diffraction was employed to analyze the crystalstructure of CYAO.It is found that the doped Ti^4+ ions do not change obviously the crystal structure of phosphors.Upon 246 nm excitation,CaYAl1-xO4:xTi^4+phosphors exhibit broad blue-violet emission band peaking at 395 nm,which can be attributed to the charge transfer of Ti^4+-O^2-.Moreover,this phosphor exhibits strong thermal stability.The luminescence emission intensity at 150℃maintained about 91 mol% of its initial value at room temperature.Additionally,the electron transition process and concentration quenching mechanism of CaYAl1-xO4:xTi^4+are discussed in detail.The excellent luminescent properties indicate that CaYAl1-xO4:xTi^4+phosphor may have promising application in indoor plant cultivation.
文摘The Eu 2+ and Dy 3+ codoped Sr 2MgSi 2O 7: Eu 2+ ,Dy 3+ blue emission long afterglow phosphor was synthesized and its photoluminescence properties were studied. It is known with the measurement method of X ray diffraction pattern that the luminescent material is an akermanite crystal. It is shown with the decay curve that its afterglow properties are better than the traditional (Ca,Sr)S:Bi blue long afterglow phosphor. Its decay curve is in accordance with the calculated results of the formula lg I=A+B 1 ×lg t +B 2×(lg t ) 2. Ther moluminescence spectra identified the existence of long afterglow luminescence. The excitation and emission spectra and microstructure of the phosphor were also investigated in detail.
基金supported by National Natural Science Foundation of China (Grant No 50872091)the Natural Science Foundation of Tianjin,China(06YFJMJC02300,06TXTJJC14602)
文摘Fluorescence enhancement of red and blue concurrently emitting Ba3MgSi2O8:Eu2+,Mn2+ phosphors for plant cultivation has been investigated by Dy3+ addition.The Ba3MgSi2O8:Eu2+,Mn2+,Dy3+(BMS-EMD) phosphors have two-color emissions at the wavelength peak values of 437 nm and 620 nm at the excitation of 350 nm.The two emission bands are coincident with the absorption spectrum for photosynthesis of plants.An obvious enhancement effect has been observed upon addition of Dy3+ with amount of 0.03 mol%,in which the ...
基金Project supported by the Science and Technology Planning Project of Zhejiang Province,China(Grant No.2018C01046)Enterprise-funded Latitudinal Research Projects,China(Grant Nos.J2016-141,J2017-171,J2017-293,and J2017-243)
文摘The color conversion glass ceramics which were made of borosilicate matrix co-doped(SrBaSm)Si2O2N2:(Eu^3+Ce^3+) blue-green phosphors were prepared by two-step method in co-sintering. The change in luminescence properties and the drift of chromaticity coordinates(CIE) of the(SrBaSm)Si2O2N2:(Eu^3+Ce^3+) blue-green phosphors and the color conversion glass ceramics were studied in the sintering temperature range from 600℃ to 800℃. The luminous intensity and internal quantum yield(QY) of the blue-green phosphors and glass ceramics decreased with the sintering temperature increasing. When the sintering temperature increased beyond 750℃, the phosphors and the color conversion glass ceramics almost had no peak in photoluminescence(PL) and excitation(PLE) spectra. The results showed that the blue-green phosphors had poor thermal stability at higher temperature. The lattice structure of the phosphors was destroyed by the glass matrix and the Ce^3+ in the phosphors was oxidized to Ce^4+, which further caused a decrease in luminescent properties of the color conversion glass ceramics.
基金supported by the Jiangsu Specially-Appointed Professorship Foundation(Grant No.1064902003)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.SJCX21_1772).
文摘The blue-emitting phosphor is one of the trichromatic phosphors essential for the development of nearultraviolet(nUV)pumped phosphor-converted white light-emitting diodes(pc-WLEDs).Efficiency and thermal stability are two critical factors for the potential application of phosphors in solid-state lighting.In this work,we report a highly efficient blue-emitting phosphor.
基金supported by the Government Funded Projects(627010104)the International Science Technology Cooperation Project of Jilin Province Science,the Technology Department(20200801038GH)the Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education,Jilin Jianzhu University(JLZHKF022021001).
文摘In the process of developing high-performance LCDs,narrow-band emitting phosphors with excellent performance are indispensable.In this study,a narrow-band blue phosphor BaZnAl_(10)O_(17):Eu^(2+)with an emission peak at 433 nm(which can be excited by near-ultraviolet light)and a full width at half maximum of 46 nm was found.The synthesized BaZnAl_(10)O_(17):Eu^(2+)phosphor exhibits low thermal quenching behavior.There is only 16.4%loss in emission intensity at 423 K compared to the initial intensity at room temperature.Using the narrow-band emission phosphor BaZnAl_(10)O_(17):Eu^(2+)as the blue light source,the prepared white LED device excited using a near-ultraviolet chip emits high-brightness white light(CCT=4436 K,R_(a)=93.96),whose CIE coordinates are(0.3387,0.3785)and CG can reach 99%of the NTSC standard.The narrow-band blue-emitting BaZnAl_(10)O_(17):Eu^(2+)phosphor has potential application value in white light-emitting diodes.
