Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red co...Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red component,it is difficult to realize warm white light efficiently.Hence,red-emitting phosphors are urgently required for improving the illumination quality.In this work,we develop a novel orangish-red La_(4)GeO_(8):Bi^(3+) phosphor,the emission peak of which is located at 600 nm under near-ultraviolet(n-UV)light excitation.The full width at half maximum(fwhm)is 103 nm,the internal quantum efficiency(IQE)exceeds 88%,and the external quantum efficiency(EQE)is 69%.According to Rietveld refinement analysis and density functional theory(DFT)calculations,Bi^(3+) ions randomly occupy all La sites in orthorhombic La_(4)GeO_(8).Importantly,the oxygen-vacancy-induced electronic localization around the Bi3+ions is the main reason for the highly efficient orangish-red luminescence.These results provide a new perspective and insight from the local electron structure for designing inorganic phosphor materials that realize the unique luminescence performance of Bi^(3+) ions.展开更多
Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high...Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high efficiency,excellent thermal stability and high colour purity is still a challenge.In this work,unique non-concentration quenching in solid-solution Cs_(3)Gd_(1-x)Ge_(3)O_(9):xEu^(3+)(CGGO:xEu^(3+))(x=0.1-1.0)phosphors is successfully developed to achieve a highly efficient red-emitting Cs_(3)EuGe_(3)0_(9)(CEGO)phosphor.Under the optimal 464 nm blue light excitation,CEGO shows a strong red emission at 611 nm with a high colour purity of 95.07%and a high internal quantum efficiency of 94%.Impressively,this red-emitting CEGO phosphor exhibits a better thermal stability at higher temperatures(175-250℃,>90%)than typical red K2SiF6:Mn^(4+)and Y203:Eu^(3+)phosphors,and has a remarkable volumetric negative thermal expansion(coefficient of thermal expansion,a=—5.06×10^(-5)/℃,25-250℃).By employing this red CEGO phosphor,a fabricated pc-WLED emits warm white light with colour coordinates(0.364,0.383),a high colour rendering index(CRI=89.7),and a low colour coordinate temperature(CCT=4508 K).These results indicate that this highly efficient red-emitting phosphor has great potential as a red component for pc-WLEDs,opening a new perspective for developing new phosphor materials.展开更多
Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,ne...Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,next-generation Cr^(3+)-free NIR-emitting phosphors with high efficiency and tunable optical properties are highly desired to enrich the types of NIR luminescent materials for different application fields.Here,we report the Fe^(3+)-activated Sr2−yCay(InSb)1−zSn_(2)zO_(6)phosphors that exhibit unprecedented long-wavelength NIR emission.The overall emission tuning from 885 to 1005 nm with broadened full-width at half maximum from 108 to 146 nm was realized through a crystallographic site engineering strategy.The NIR emission was significantly enhanced after complete Ca^(2+)incorporation owing to the substitution-induced lower symmetry of the Fe^(3+)sites.The Ca_(2)InSbO_(6):Fe^(3+)phosphor peaking at 935 nm showed an ultra-high internal quantum efficiency of 87%.The as-synthesized emission-tunable phosphors demonstrated great potential for NIR spectroscopy detection.This work initiates the development of efficient Fe^(3+)-activated broadband NIR-emitting phosphors and opens up a new avenue for designing NIR-emitting phosphor materials.展开更多
Achievement of high photoluminescence quantum efficiency and thermal stability is challenging for near-infrared(NIR)-emitting phosphors.Here,we designed a“kill two birds with one stone”strategy to simultaneously imp...Achievement of high photoluminescence quantum efficiency and thermal stability is challenging for near-infrared(NIR)-emitting phosphors.Here,we designed a“kill two birds with one stone”strategy to simultaneously improve quantum efficiency and thermal stability of the NIR-emitting Ca_(3)Y_(2-2x)(ZnZr)_(x)Ge_(3)O_(12):Cr garnet system by chemical unit cosubstitution,and revealed universal structure-property relationship and the luminescence optimization mechanism.The cosubstitution of[Zn^(2+)-Zr^(4+)]for[Y^(3+)-Y^(3+)]played a critical role as reductant to promote the valence transformation from Cr^(4+)to Cr^(3+),resulting from the reconstruction of octahedral sites for Cr^(3+).The introduction of[Zn^(2+)-Zr^(4+)]unit also contributed to a rigid crystal structure.These two aspects together realized the high internal quantum efficiency of 96%and excellent thermal stability of 89%@423 K.Moreover,information encryption with“burning after reading”was achieved based on different chemical resistance of the phosphors to acid.The developed NIR-emitting phosphor-converted light-emitting diode demonstrated promising applications in bio-tissue imaging and night vision.This work provides a new perspective for developing high-performance NIR-emitting phosphor materials.展开更多
Early detection of cancer biomarkers applied in real-time disease diagnosis and therapies can increase the survival rate of patients.Circulating tumor DNA(ct DNA)as a typical cancer biomarker plays a great role in the...Early detection of cancer biomarkers applied in real-time disease diagnosis and therapies can increase the survival rate of patients.Circulating tumor DNA(ct DNA)as a typical cancer biomarker plays a great role in the process of tumor disease monitoring,especially in early diagnosis.Unfortunately,most ct DNA detection systems have not been widely used due to their low sensitivity,poor specificity,and high cost.Herein,we developed an alternative ct DNA detection system to present the levels of ct DNA by recording the fluorescence signals of the system containing upconversion nanoparticles(UCNPs),Fe_(3)O_(4),and entropy-driven strand displacement reaction.The method has a practical sensitivity with a wide linear range from 100 amol L^(-1)to 1 nmol L^(-1)and a low detection limit of 1.6 amol L^(-1).Furthermore,the system demonstrates a practical application in mouse blood serum samples and meets the requirements for rapid,sensitive,specific,and economical diagnosis of cancers.Thus,this ct DNA detection system may have great potential for ct DNAdetection and clinical diagnosis.展开更多
Near-infrared(NIR)luminescent metal halide(LMH)materials have attracted great attention in various optoelectronic applications due to their low-temperature solution-processable synthesis,abundant crystallographic/elec...Near-infrared(NIR)luminescent metal halide(LMH)materials have attracted great attention in various optoelectronic applications due to their low-temperature solution-processable synthesis,abundant crystallographic/electronic structures,and unique optoelectronic properties.However,some challenges still remain in their luminescence design,performance improvement,and application assign-ments.This review systematically summarizes the development of NIR LMHs through classifying NIR luminescent origins into four major categories:band-edge emission,self-trapped exciton(STE)emission,ion emission,and defect-related emission.The luminescence mechanisms of different types of NIR LMHs are discussed in detail by analyzing typical examples.Reasonable strategies for design-ing and optimizing luminescence/optoelectronic properties of NIR LMHs are summarized,including bandgap engineering,self-trapping state engineering,chemical composition modification,energy transfer,and other auxiliary strategies such as improvement of synthesis scheme and post-processing.Furthermore,application prospects based on the optoelectronic devices are revealed,including phosphor-converted light-emitting diodes(LEDs),electroluminescent LEDs,pho-todetectors,solar cells,and x-ray scintillators,as well as demonstrations of some related practical applications.Finally,the existing challenges and future perspec-tives on the development of NIR LMH materials are critically proposed.This review aims to provide general understanding and guidance for the design of high-performance NIR LMHs materials.展开更多
基金supported by the National Natural Science Foundation of China(Grants Nos.51672259,51720105015,51672265,21521092,51750110511,and 21872174)Key Research Program of Frontier Sciences of CAS(YZDY-SSWJSC018)+8 种基金the CAS-Croucher Funding Scheme for Joint Laboratories(CAS18204)the Scientific and Technological Department of Jilin Province(Grant No.20170414003GH)Project of Innovation-Driven Plan in Central South University(2017CX003)State Key Laboratory of Powder Metallurgy in Central South UniversityThousand Youth Talents Plan of ChinaHundred Youth Talents Program of HunanShenzhen Science and Technology Innovation Project(630)Jiangmen Innovative Research Team Program(2017)Major program of basic research and applied research of Guangdong Province(2017KZDXM083).
文摘Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red component,it is difficult to realize warm white light efficiently.Hence,red-emitting phosphors are urgently required for improving the illumination quality.In this work,we develop a novel orangish-red La_(4)GeO_(8):Bi^(3+) phosphor,the emission peak of which is located at 600 nm under near-ultraviolet(n-UV)light excitation.The full width at half maximum(fwhm)is 103 nm,the internal quantum efficiency(IQE)exceeds 88%,and the external quantum efficiency(EQE)is 69%.According to Rietveld refinement analysis and density functional theory(DFT)calculations,Bi^(3+) ions randomly occupy all La sites in orthorhombic La_(4)GeO_(8).Importantly,the oxygen-vacancy-induced electronic localization around the Bi3+ions is the main reason for the highly efficient orangish-red luminescence.These results provide a new perspective and insight from the local electron structure for designing inorganic phosphor materials that realize the unique luminescence performance of Bi^(3+) ions.
基金supported by the National Natural Science Foundation of China(NSFC Nos.51932009,51929201,51672265,51672266,51750110511,51672257,52072349 and 51672259)Science and Technology Cooperation Project between Chinese and Australian Governments(2017YFE0132300)+1 种基金the Key Research Programme of Frontier Sciences,CAS(Grant No.YZDY-SSW-JSC018)Jiangmen Innovative Research Team Programme(2017)and Major Programme of Basic Research and Applied Research of Guangdong Province(2017KZDXM083).
文摘Red phosphor materials play a key role in improving the lighting and backlit display quality of phosphor-converted white light-emitting diodes(pc-WLEDs).However,the development of a red phosphor with simultaneous high efficiency,excellent thermal stability and high colour purity is still a challenge.In this work,unique non-concentration quenching in solid-solution Cs_(3)Gd_(1-x)Ge_(3)O_(9):xEu^(3+)(CGGO:xEu^(3+))(x=0.1-1.0)phosphors is successfully developed to achieve a highly efficient red-emitting Cs_(3)EuGe_(3)0_(9)(CEGO)phosphor.Under the optimal 464 nm blue light excitation,CEGO shows a strong red emission at 611 nm with a high colour purity of 95.07%and a high internal quantum efficiency of 94%.Impressively,this red-emitting CEGO phosphor exhibits a better thermal stability at higher temperatures(175-250℃,>90%)than typical red K2SiF6:Mn^(4+)and Y203:Eu^(3+)phosphors,and has a remarkable volumetric negative thermal expansion(coefficient of thermal expansion,a=—5.06×10^(-5)/℃,25-250℃).By employing this red CEGO phosphor,a fabricated pc-WLED emits warm white light with colour coordinates(0.364,0.383),a high colour rendering index(CRI=89.7),and a low colour coordinate temperature(CCT=4508 K).These results indicate that this highly efficient red-emitting phosphor has great potential as a red component for pc-WLEDs,opening a new perspective for developing new phosphor materials.
基金financially supported by the National Natural Science Foundation of China(NSFC Nos.51720105015,51932009,51929201,52072349)the Projects for Science and Technology Development Plan of Jilin Province(20210402046GH)the Natural Science Foundation of Zhejiang Province(LR22E020004).
文摘Near-infrared(NIR)-emitting phosphor-converted light-emitting diodes have attracted widespread attention in various applications based on NIR spectroscopy.Except for typical Cr^(3+)-activated NIR-emitting phosphors,next-generation Cr^(3+)-free NIR-emitting phosphors with high efficiency and tunable optical properties are highly desired to enrich the types of NIR luminescent materials for different application fields.Here,we report the Fe^(3+)-activated Sr2−yCay(InSb)1−zSn_(2)zO_(6)phosphors that exhibit unprecedented long-wavelength NIR emission.The overall emission tuning from 885 to 1005 nm with broadened full-width at half maximum from 108 to 146 nm was realized through a crystallographic site engineering strategy.The NIR emission was significantly enhanced after complete Ca^(2+)incorporation owing to the substitution-induced lower symmetry of the Fe^(3+)sites.The Ca_(2)InSbO_(6):Fe^(3+)phosphor peaking at 935 nm showed an ultra-high internal quantum efficiency of 87%.The as-synthesized emission-tunable phosphors demonstrated great potential for NIR spectroscopy detection.This work initiates the development of efficient Fe^(3+)-activated broadband NIR-emitting phosphors and opens up a new avenue for designing NIR-emitting phosphor materials.
基金This work was financially supported by the National Science and Technology Major Project(2022YFB3503800)the National Natural Science Foundation of China(NSFC Nos.51932009,51929201,52072349,52172166,12374386,12374388,12304461,U2005212)+1 种基金the Natural Science Foundation of Zhejiang Province(LR22E020004)the Project funded by China Postdoctoral Science Foundation(2022TQ0365,2023M733436).
文摘Achievement of high photoluminescence quantum efficiency and thermal stability is challenging for near-infrared(NIR)-emitting phosphors.Here,we designed a“kill two birds with one stone”strategy to simultaneously improve quantum efficiency and thermal stability of the NIR-emitting Ca_(3)Y_(2-2x)(ZnZr)_(x)Ge_(3)O_(12):Cr garnet system by chemical unit cosubstitution,and revealed universal structure-property relationship and the luminescence optimization mechanism.The cosubstitution of[Zn^(2+)-Zr^(4+)]for[Y^(3+)-Y^(3+)]played a critical role as reductant to promote the valence transformation from Cr^(4+)to Cr^(3+),resulting from the reconstruction of octahedral sites for Cr^(3+).The introduction of[Zn^(2+)-Zr^(4+)]unit also contributed to a rigid crystal structure.These two aspects together realized the high internal quantum efficiency of 96%and excellent thermal stability of 89%@423 K.Moreover,information encryption with“burning after reading”was achieved based on different chemical resistance of the phosphors to acid.The developed NIR-emitting phosphor-converted light-emitting diode demonstrated promising applications in bio-tissue imaging and night vision.This work provides a new perspective for developing high-performance NIR-emitting phosphor materials.
基金supported by the Science and Technology Cooperation Project between Chinese and Australian Governments (2017YFE0132300)the National Natural Science Foundation of China (NSFC 51929201, 51672268, 51720105015, 51972138, 51872263, and 51828202)+1 种基金the Science and Technology Development Planning Project of Jilin Province (20190201232JC)the CASCroucher Funding Scheme for Joint Laboratories (CAS18204)
文摘Early detection of cancer biomarkers applied in real-time disease diagnosis and therapies can increase the survival rate of patients.Circulating tumor DNA(ct DNA)as a typical cancer biomarker plays a great role in the process of tumor disease monitoring,especially in early diagnosis.Unfortunately,most ct DNA detection systems have not been widely used due to their low sensitivity,poor specificity,and high cost.Herein,we developed an alternative ct DNA detection system to present the levels of ct DNA by recording the fluorescence signals of the system containing upconversion nanoparticles(UCNPs),Fe_(3)O_(4),and entropy-driven strand displacement reaction.The method has a practical sensitivity with a wide linear range from 100 amol L^(-1)to 1 nmol L^(-1)and a low detection limit of 1.6 amol L^(-1).Furthermore,the system demonstrates a practical application in mouse blood serum samples and meets the requirements for rapid,sensitive,specific,and economical diagnosis of cancers.Thus,this ct DNA detection system may have great potential for ct DNAdetection and clinical diagnosis.
基金financially supported by the National Science and Technology Major Project(2023YFB3506600)the National Natural Science Foundation of China(NSFC Nos.12374386,12374388,12304461,52072349)+1 种基金the Natural Science Foundation of Zhejiang Province(LR22E020004)the China Postdoctoral Science Foundation(2022TQ0365,2023M733436).
文摘Near-infrared(NIR)luminescent metal halide(LMH)materials have attracted great attention in various optoelectronic applications due to their low-temperature solution-processable synthesis,abundant crystallographic/electronic structures,and unique optoelectronic properties.However,some challenges still remain in their luminescence design,performance improvement,and application assign-ments.This review systematically summarizes the development of NIR LMHs through classifying NIR luminescent origins into four major categories:band-edge emission,self-trapped exciton(STE)emission,ion emission,and defect-related emission.The luminescence mechanisms of different types of NIR LMHs are discussed in detail by analyzing typical examples.Reasonable strategies for design-ing and optimizing luminescence/optoelectronic properties of NIR LMHs are summarized,including bandgap engineering,self-trapping state engineering,chemical composition modification,energy transfer,and other auxiliary strategies such as improvement of synthesis scheme and post-processing.Furthermore,application prospects based on the optoelectronic devices are revealed,including phosphor-converted light-emitting diodes(LEDs),electroluminescent LEDs,pho-todetectors,solar cells,and x-ray scintillators,as well as demonstrations of some related practical applications.Finally,the existing challenges and future perspec-tives on the development of NIR LMH materials are critically proposed.This review aims to provide general understanding and guidance for the design of high-performance NIR LMHs materials.
