Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properti...Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging.展开更多
Recently,there has been a global movement toward environmental protection and energy conservation through the design and development of new products in accordance with sustainable utilisation.In this study,rare earth ...Recently,there has been a global movement toward environmental protection and energy conservation through the design and development of new products in accordance with sustainable utilisation.In this study,rare earth luminescent materials were used owing to their active light emission and reusability.Additionally,solar lightemitting diode lights and car-light reflection were utilised to increase the recognition and reliability of reflective cat eyes.Along with carbon reduction,this can save energy and enhance road safety.This study considered the Theory of Inventive Problem Solving and a literature review to analyse the issues in existing products.Then,expert interviews were conducted to screen projects and develop product design policies.Finally,the ratio of light-storage materials was experimentally determined and the prototypes implemented.This cat’s eye addresses the shortcomings identified in previous analyses of existing products.We applied energy storage environmental protection materials,together with material proportioning(which balanced warning efficiency against cost-effectiveness)to develop diversified modular kits;these were flexible in terms of quantity and easily assembled.This study achieved four key objectives:(1)reducing the research and development costs of the manufacturer;(2)offering buyers a diverse suite of products;(3)responding to a need to improve diverse road user safety;and(4)reducing government procurement costs for safety warning products.The results provide a reference for the creative modular design of energy-saving products for public road safety planning in various industries.展开更多
Due to the outbreak of |x-19,colleges and universities have actively responded to the call of the state to carry out online teaching in completing their teaching tasks.After the epidemic,the online and offline hybrid ...Due to the outbreak of |x-19,colleges and universities have actively responded to the call of the state to carry out online teaching in completing their teaching tasks.After the epidemic,the online and offline hybrid teaching has become a novel mode of teaching which meets the requirements of teaching reform and the information society.This teaching method integrates both the online and offline teaching which plays an important role in enhancing teaching qualities and learning experiences.However,due to the lack of experience,there are some issues occurring in the teaching process of this method.The Luminescent Materials and Applications course is used as the subject in this article.The difficulties in traditional offline teaching as well as the advantages,detailed course construction process,and effectiveness evaluation of hybrid teaching are summarized and meticulously analyzed.In regard to that,the application of the online and offline hybrid teaching in the Luminescent Materials and Applications course is beneficial to the learning of professional knowledge and the cultivation of students'scientific literacy.Therefore,it is an effective way to improve and enrich this course by using the online and offline hybrid teaching method.展开更多
Benefited from direct generation of circularly polarized(CP) emission with tunable colors, high efficiencies and facile device architectures, CP organic light-emitting diodes(CP-OLEDs) have attracted great attention a...Benefited from direct generation of circularly polarized(CP) emission with tunable colors, high efficiencies and facile device architectures, CP organic light-emitting diodes(CP-OLEDs) have attracted great attention and are expected to meet industrial applications. Particularly, CP electroluminescence(CPEL) originated from CP-OLEDs has wide potential applications in 3D displays, optical information storage, quantum communication, and biological sensors. The diverse design strategies of chiral luminescent materials for CP-OLEDs, including small organic emitters, lanthanide and transition-metal complexes and conjugated polymers, have been extensively explored. Helicene with twisted extended π-conjugated molecular structure could exhibit special helical chirality and excellent circularly polarized luminescence properties, which has been employed as the ingenious chirality core for constructing efficient chiral luminescent materials. In addition, significant improvements have been made in terms of CP photoluminescence research, however, the development of CPEL with more application prospects in optoelectronic technology still lags behind. In this review, we systematically summarize the recent advances in chiral luminescent materials based on helicene structure and their CPEL properties, including helicene-based chiral fluorescence molecules, transition metal complexes and thermally activated delayed fluorescence molecules, and discuss current challenges and future perspectives for this hot research field. We believe this progress report will provide a promising perspective of OLEDs based on helicene emitters with CPEL properties for extensive researchers, including chemical, physical and material scientists in different disciplinary fields and attract them to this rapidly developing field.展开更多
1 Results The size of nanoscale rare earth luminescent materials is often smaller than that of the excitement or emission wavelength,and it has amazing surface state density. Therefore,it shows a lot of new luminescen...1 Results The size of nanoscale rare earth luminescent materials is often smaller than that of the excitement or emission wavelength,and it has amazing surface state density. Therefore,it shows a lot of new luminescent phenomena such as the shift of CTS,the broadening of emission peaks,the variation of fluorescent lifetimes and quantum efficiency,and the increase of quenching concentration.It is not only of academic interest but also of technological importance for advanced phosphor applications to rese...展开更多
Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregn...Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of Eu3+ under UV light exci-tation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.展开更多
A series of star-shaped molecules with benzene core and naphthalimides derivatives end groups have been designed to explore their optical,electronic,and charge transport properties as charge transport and/or luminesce...A series of star-shaped molecules with benzene core and naphthalimides derivatives end groups have been designed to explore their optical,electronic,and charge transport properties as charge transport and/or luminescent materials for organic light-emitting diodes(OLEDs). The frontier molecular orbitals(FMOs) analysis has turned out that the vertical electronic transitions of absorption and emission are characterized as intramolecular charge transfer(ICT). The calculated results show that the optical and electronic properties of star-shaped molecules are affected by the substituent groups in N-position of 1,8-naphthalimide ring. Our results suggest that star-shaped molecules with n-butyl(1),benzene(2),thiophene(3),thiophene S?,S?-dioxide(4),benzo[c][1,2,5]thiadiazole(5),and 2,7a-dihydrobenzo[d]thiazole(6) fragments are expected to be promising candidates for luminescent and electron transport materials for OLEDs. This study should be helpful in further theoretical investigations on such kind of systems and also to the experimental study for charge transport and/or luminescent materials for OLEDs.展开更多
The large size of lasers limits their applications in confined spaces,such as in biosensing and in vivo brain tissue imaging.In this regard,micron-sized lasers have been developed.They exhibit great potential for biol...The large size of lasers limits their applications in confined spaces,such as in biosensing and in vivo brain tissue imaging.In this regard,micron-sized lasers have been developed.They exhibit great potential for biological detecting,remote sensing,and depth tracking due to their small sizes,sensitive properties of their spectral fingerprints,and flexible positional modulation in the microenvironment.Lanthanide-based luminescent materials that possess long excited-state lifetime,narrow emission bandwidth,and upconversion behaviors are promising as gain mediums for novel microlasers.In addition,lanthanide-based microlasers could be generated under natural ambient conditions with pumped or continuous light sources,which significantly promotes the practical applications of microlasers.Recent progress in the design,synthesis,and biomedical applications of lanthanide-based microlasers has been outlined in this review.Lanthanide ions doped and upconverted lanthanide-based microlasers are highlighted,which exhibit advantageous structures,miniaturized dimensions,and high lasing performance.The applications of lanthanide-based microlasers are further discussed,the upconverted microlasers show great advantages for biological applications owing to their tunable excitation and emission characteristics and excellent environmental stability.Moreover,perspectives and challenges in the field of lanthanide-based microlasers are presented.展开更多
The research of purely organic materials with long afterglow has drawn more and more attention,especially for those with stimulus‐response characteristic.So far,this kind of material is really very scarce and their p...The research of purely organic materials with long afterglow has drawn more and more attention,especially for those with stimulus‐response characteristic.So far,this kind of material is really very scarce and their performance is not good enough.In this study,we successfully developed an efficient heatingresponsive room‐temperature phosphorescence material with phosphorescence efficiency and lifetime up to 13.4%and 2.08 s through the simple host–guest doping strategy.Further on,by introducing the additional energy acceptor of fluorescein with concentration‐dependent emission to construct ternary doping systems,the afterglow color was extended from blue to yellow.Accordingly,the multicolor thermal printings have been easily realized,showing the great practical application prospects.展开更多
Boron-containing molecules and polymers are attractive as powerful tunable Lewis acids for small molecule activation and catalysis,as luminescent materials for organic electronic device and(bio)imaging applications,an...Boron-containing molecules and polymers are attractive as powerful tunable Lewis acids for small molecule activation and catalysis,as luminescent materials for organic electronic device and(bio)imaging applications,and as smart chemical sensors.While the characteristics of the boron-containing building blocks are attractive in and of themselves,their assembly into higher order supramolecular materials offers access to unique properties and emerging functions.Herein,we highlight recent achievements in the field of aggregated organoboron materials.We discuss how supramolecular interactions can be exploited to precisely control the structure of the assemblies and impact their functions as luminescent materials,recyclable and smart catalyst systems,chemical sensors,stimuli-responsive and self-healing materials.展开更多
Recently,high-performance color converters excitable by blue laser diode(LD)have sprung up for projection displays.However,the thermal accumulation effect of the color converters is a non-negligible problem under high...Recently,high-performance color converters excitable by blue laser diode(LD)have sprung up for projection displays.However,the thermal accumulation effect of the color converters is a non-negligible problem under high-power LD irradiation.Herein,we developed novel opto-functional composites(patterned CaAlSiN3:Eu^(2+)phosphor-in-glass film–Y_(3)Al_(5)O_(12):Ce^(3+)phosphor-in-glass film@Al_(2)O_(3)plate with aluminum"heat sink")via a thermal management methodology of combining"phosphor wheel"and"heat sink"for a lighting source of highpower laser projection displays.This new composite design makes it effective to transport generated thermal phonons away to reduce the thermal ionization process,and to yield stable and high-quality white light with brightness of 4510 lm@43 W,luminous efficacy of 105 lm/W,correlated color temperature of 3541 K,and color rendering index of 80.0.Furthermore,the phosphor-in-glass film-converted laser projection system was also successfully designed,showing a more vivid color effect compared to a traditional LED-based projector.This work emphasizes the importance of the thermal management upon high-power laser irradiation,and hopefully facilitates the development of a new LD-driven lighting source for high-power laser projection displays.展开更多
Constructing blue thermally activated delayedfluorescence materials for high-performance organic light-emitting diodes(OLEDs)remains challenging due to the intrinsically strong intramolecular charge transfer nature of...Constructing blue thermally activated delayedfluorescence materials for high-performance organic light-emitting diodes(OLEDs)remains challenging due to the intrinsically strong intramolecular charge transfer nature of the nearly orthogonal connection of electron donor(D)and acceptor(A),which results in long-wavelength emission.Herein,an effective delayed-fluorescence design strategy of modulating D–A torsion angles is proposed and efficient sky-blue,pure-blue,and deep-blue delayed-fluorescence molecules consisting of a xanthenone acceptor and carbazole-based donors are created by decreasing the torsion angles.They exhibit strong delayed fluorescence with high photoluminescence quantum yields of 85–94%in doped films,and their delayed-fluorescence lifetimes are elongated from 1.0 to 27.6μs as the torsion angles decrease.These molecules can function as excellent emitters in OLEDs,providing efficient electroluminescence peaking at 442 nm(CIEx,y=0.15,0.08),462 nm(CIEx,y=0.15,0.18),and 482 nm(CIEx,y=0.17,0.30)with state-of-the-art external quantum efficiencies of up to 22.2%,33.7%,and 32.1%,respectively,demonstrating the proposed molecular design for efficient blue delayed-fluorescence molecules is successful and promising.展开更多
Aggregation-induced emission(AIE),as an exciting photophysical phenomenon,has been regarded as one frontier research topic within both ranges of molecular luminescence and materials science over the last two decades.S...Aggregation-induced emission(AIE),as an exciting photophysical phenomenon,has been regarded as one frontier research topic within both ranges of molecular luminescence and materials science over the last two decades.Since controllable molecular ensembles with particular morphologies and tunable functions can be elegantly constructed in the realm of supramolecular chemistry,the integration of supramolecular assembly and AIE systems can expectedly bring about luminescent materials with tunable emission and tailorable well-ordered architectures.In this review,we will provide a summary of the creation and working mechanisms of AIE systems involving supramolecular systems that are driven by different supramolecular driving forces including hydrogen bonding,host−guest interactions,metal coordination,and π-π interactions.The morphological and photoluminescent features of these AIE-active supramolecular assemblies will be elucidated,and the regulated fluorescence properties of the AIEgens induced by the assembling-disassembling processes will be discussed in detail.展开更多
To introduce ordered nano-structures inside a transparent amorphous matrix with superior optical and mechanical properties bears scientific and technological importance,yet limited success has been achieved.Here,via s...To introduce ordered nano-structures inside a transparent amorphous matrix with superior optical and mechanical properties bears scientific and technological importance,yet limited success has been achieved.Here,via simple melting-quenching and subsequent thermal activation,we report the successful preparation of transparent nano-structured glass-ceramics embedded in Sr2Lu F7 nano-crystals(~26 nm),as evidenced by X-ray diffraction,transmission electron microscopy(TEM),and high resolution TEM.The successful incorporation of dopants into formed Sr2Lu F7 nano-crystals with low phonon energy results in highly tunable blue–green photoemission,which depends on excitation wavelength,dopant type,and temperature.We found that Eu3+and Eu2+ions co-exist in this hybrid optical material,accompanied by the broadband blue emission of Eu2+and sharp red emissions of Eu3+.A series of optical characterizations are summoned,including emission/excitation spectrum and decay curve measurement,to reveal the reduction mechanism of Eu3+to Eu2+.Furthermore,near green–white photoemission is achieved via the enrichment of Tb3+/Eu3+into crystallized Sr2Lu F7 nano-crystals.The temperature-dependent visible photoemission reveals thermal activation energy increases with the precipitation of Sr2Lu F7 nano-crystals in a glass matrix,suggesting better thermal stability of glass-ceramics than precursor glasses.These results could not only deepen the understanding of glass-ceramics but also indicate the promising potential of Eu3+/Tb3+-ions-doped Sr2Lu F7 glass-ceramics for UV pumped white light emitting diodes(WLEDs)with good thermal stability.展开更多
A highly efficient redox-and step-economic method to synthesize N,O-and O,O-difluoroboron complexes from alkynes under aqueous condition with HBF_(4) as BF_(2) source has been developed.This strategy features good yie...A highly efficient redox-and step-economic method to synthesize N,O-and O,O-difluoroboron complexes from alkynes under aqueous condition with HBF_(4) as BF_(2) source has been developed.This strategy features good yields,broad substrate scope,mild reaction conditions,readily available starting materials and gram-scale synthesis.Significantly,these difluoroboron complexes present good fluorescence properties,indicating their potential applications in luminescent materials.展开更多
Forsterite particles doped with europium ions(Eu^(3+)) were synthesized via a solution combustion method. The effect of co-dopants on photoluminescence intensity was described. Different percentages of calcium(Ca^(2+)...Forsterite particles doped with europium ions(Eu^(3+)) were synthesized via a solution combustion method. The effect of co-dopants on photoluminescence intensity was described. Different percentages of calcium(Ca^(2+)), zinc(Zn^(2+)), barium(Ba^(2+)) and strontium(Sr^(2+)) were added to the Mg_2SiO_4:Eu^(3+)host.The synthesized sample was characterized by X-ray diffraction, transmission electron microscopy,scanning electron microscopy, spectrofluorometer and the FTIR spectroscopy. X-ray diffraction(XRD)results revealed that dominant phase was forsterite in all samples. Additionally, a negligible amount of periclase phase was recognized in the samples. The average size of the synthesized particles was less than 200 nm. The presence of co-dopant led to an enhancement in the photoluminescent property of the synthesized samples. The maximum increase in photoluminescence intensity was obtained by Ba^(2+)ions as a co-dopant. Condensed films of photoluminescence particles were produced by utilizing electrophoresis technique to deposit particles. The results showed that polyvinyl pyrrolidone was the best surface modifier to raise the mass deposition of the samples on the substrate.展开更多
文摘Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging.
基金This work was supported by Ministry of Science and Technology funded by the Taiwan Government[Grant No.MOST 105-2622-E-327-011-CC3]However,the publication of our work is fully in MOST’s favor.
文摘Recently,there has been a global movement toward environmental protection and energy conservation through the design and development of new products in accordance with sustainable utilisation.In this study,rare earth luminescent materials were used owing to their active light emission and reusability.Additionally,solar lightemitting diode lights and car-light reflection were utilised to increase the recognition and reliability of reflective cat eyes.Along with carbon reduction,this can save energy and enhance road safety.This study considered the Theory of Inventive Problem Solving and a literature review to analyse the issues in existing products.Then,expert interviews were conducted to screen projects and develop product design policies.Finally,the ratio of light-storage materials was experimentally determined and the prototypes implemented.This cat’s eye addresses the shortcomings identified in previous analyses of existing products.We applied energy storage environmental protection materials,together with material proportioning(which balanced warning efficiency against cost-effectiveness)to develop diversified modular kits;these were flexible in terms of quantity and easily assembled.This study achieved four key objectives:(1)reducing the research and development costs of the manufacturer;(2)offering buyers a diverse suite of products;(3)responding to a need to improve diverse road user safety;and(4)reducing government procurement costs for safety warning products.The results provide a reference for the creative modular design of energy-saving products for public road safety planning in various industries.
基金supported by the 2019-2021 Undergraduate Teaching Project of Chengdu University of Information Technology(BKJX2020022,BKJX2020081)Department of Human Resources and Social Security of Sichuan Province(2019Z226).
文摘Due to the outbreak of |x-19,colleges and universities have actively responded to the call of the state to carry out online teaching in completing their teaching tasks.After the epidemic,the online and offline hybrid teaching has become a novel mode of teaching which meets the requirements of teaching reform and the information society.This teaching method integrates both the online and offline teaching which plays an important role in enhancing teaching qualities and learning experiences.However,due to the lack of experience,there are some issues occurring in the teaching process of this method.The Luminescent Materials and Applications course is used as the subject in this article.The difficulties in traditional offline teaching as well as the advantages,detailed course construction process,and effectiveness evaluation of hybrid teaching are summarized and meticulously analyzed.In regard to that,the application of the online and offline hybrid teaching in the Luminescent Materials and Applications course is beneficial to the learning of professional knowledge and the cultivation of students'scientific literacy.Therefore,it is an effective way to improve and enrich this course by using the online and offline hybrid teaching method.
基金National Natural Science Foundation of China(No.22005158)Program of High Level Talents(Nos.03083064 and JSSCBS20211122)Large Instruments Open Foundation of Nantong University.
文摘Benefited from direct generation of circularly polarized(CP) emission with tunable colors, high efficiencies and facile device architectures, CP organic light-emitting diodes(CP-OLEDs) have attracted great attention and are expected to meet industrial applications. Particularly, CP electroluminescence(CPEL) originated from CP-OLEDs has wide potential applications in 3D displays, optical information storage, quantum communication, and biological sensors. The diverse design strategies of chiral luminescent materials for CP-OLEDs, including small organic emitters, lanthanide and transition-metal complexes and conjugated polymers, have been extensively explored. Helicene with twisted extended π-conjugated molecular structure could exhibit special helical chirality and excellent circularly polarized luminescence properties, which has been employed as the ingenious chirality core for constructing efficient chiral luminescent materials. In addition, significant improvements have been made in terms of CP photoluminescence research, however, the development of CPEL with more application prospects in optoelectronic technology still lags behind. In this review, we systematically summarize the recent advances in chiral luminescent materials based on helicene structure and their CPEL properties, including helicene-based chiral fluorescence molecules, transition metal complexes and thermally activated delayed fluorescence molecules, and discuss current challenges and future perspectives for this hot research field. We believe this progress report will provide a promising perspective of OLEDs based on helicene emitters with CPEL properties for extensive researchers, including chemical, physical and material scientists in different disciplinary fields and attract them to this rapidly developing field.
文摘1 Results The size of nanoscale rare earth luminescent materials is often smaller than that of the excitement or emission wavelength,and it has amazing surface state density. Therefore,it shows a lot of new luminescent phenomena such as the shift of CTS,the broadening of emission peaks,the variation of fluorescent lifetimes and quantum efficiency,and the increase of quenching concentration.It is not only of academic interest but also of technological importance for advanced phosphor applications to rese...
基金financial supportfrom PRAMX 98-05 and helpful discussion with Dr.A.C.Franville.
文摘Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of Eu3+ under UV light exci-tation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.
基金Support by the National Natural Science Foundation of China(No.21563002)the Natural Science Foundation of Inner Mongolia Autonomous Region(No.2015MS0201)the Research Program of Sciences at Universities of Inner Mongolia Autonomous Region(No.NJZZ235)
文摘A series of star-shaped molecules with benzene core and naphthalimides derivatives end groups have been designed to explore their optical,electronic,and charge transport properties as charge transport and/or luminescent materials for organic light-emitting diodes(OLEDs). The frontier molecular orbitals(FMOs) analysis has turned out that the vertical electronic transitions of absorption and emission are characterized as intramolecular charge transfer(ICT). The calculated results show that the optical and electronic properties of star-shaped molecules are affected by the substituent groups in N-position of 1,8-naphthalimide ring. Our results suggest that star-shaped molecules with n-butyl(1),benzene(2),thiophene(3),thiophene S?,S?-dioxide(4),benzo[c][1,2,5]thiadiazole(5),and 2,7a-dihydrobenzo[d]thiazole(6) fragments are expected to be promising candidates for luminescent and electron transport materials for OLEDs. This study should be helpful in further theoretical investigations on such kind of systems and also to the experimental study for charge transport and/or luminescent materials for OLEDs.
基金supported by the National Key R&D Program of China (2021YFB3500400)the Autonomous Deployment Project of Haixi Institute,Chinese Academy of Sciences (CXZX-2022-GH11)。
基金supported by the National Natural Science Foundation of China(Nos.22020102003,22207104,and 22125701)the National Key R&D Program of China(Nos.2022YFF071000 and 2021YFF0701800)+2 种基金Natural Science Foundation of Jilin Province(No.20230101102JC)China Postdoctoral Science Foundation(Nos.2020M681055 and 2022T150634)Young Elite Scientists Sponsorship Program by CAST(Nos.2021-2023QNRC and YESS20210067).
文摘The large size of lasers limits their applications in confined spaces,such as in biosensing and in vivo brain tissue imaging.In this regard,micron-sized lasers have been developed.They exhibit great potential for biological detecting,remote sensing,and depth tracking due to their small sizes,sensitive properties of their spectral fingerprints,and flexible positional modulation in the microenvironment.Lanthanide-based luminescent materials that possess long excited-state lifetime,narrow emission bandwidth,and upconversion behaviors are promising as gain mediums for novel microlasers.In addition,lanthanide-based microlasers could be generated under natural ambient conditions with pumped or continuous light sources,which significantly promotes the practical applications of microlasers.Recent progress in the design,synthesis,and biomedical applications of lanthanide-based microlasers has been outlined in this review.Lanthanide ions doped and upconverted lanthanide-based microlasers are highlighted,which exhibit advantageous structures,miniaturized dimensions,and high lasing performance.The applications of lanthanide-based microlasers are further discussed,the upconverted microlasers show great advantages for biological applications owing to their tunable excitation and emission characteristics and excellent environmental stability.Moreover,perspectives and challenges in the field of lanthanide-based microlasers are presented.
基金National Natural Science Foundation of China,Grant/Award Number:51903188Natural Science Foundation of Tianjin City,Grant/Award Number:19JCQNJC04500The starting Grants of Tianjin University and Tianjin Government。
文摘The research of purely organic materials with long afterglow has drawn more and more attention,especially for those with stimulus‐response characteristic.So far,this kind of material is really very scarce and their performance is not good enough.In this study,we successfully developed an efficient heatingresponsive room‐temperature phosphorescence material with phosphorescence efficiency and lifetime up to 13.4%and 2.08 s through the simple host–guest doping strategy.Further on,by introducing the additional energy acceptor of fluorescein with concentration‐dependent emission to construct ternary doping systems,the afterglow color was extended from blue to yellow.Accordingly,the multicolor thermal printings have been easily realized,showing the great practical application prospects.
文摘Boron-containing molecules and polymers are attractive as powerful tunable Lewis acids for small molecule activation and catalysis,as luminescent materials for organic electronic device and(bio)imaging applications,and as smart chemical sensors.While the characteristics of the boron-containing building blocks are attractive in and of themselves,their assembly into higher order supramolecular materials offers access to unique properties and emerging functions.Herein,we highlight recent achievements in the field of aggregated organoboron materials.We discuss how supramolecular interactions can be exploited to precisely control the structure of the assemblies and impact their functions as luminescent materials,recyclable and smart catalyst systems,chemical sensors,stimuli-responsive and self-healing materials.
基金supported by National Key R&D Program of China(No.2021YFB3500503)National Natural Science Foundation of China(Nos.52272141,51972060,12074068,52102159,and 22103013)Natural Science Foundation of FujianProvince(Nos.2022J05091,2020J02017,2021J06021,2021J01190,and 2020J01931).
文摘Recently,high-performance color converters excitable by blue laser diode(LD)have sprung up for projection displays.However,the thermal accumulation effect of the color converters is a non-negligible problem under high-power LD irradiation.Herein,we developed novel opto-functional composites(patterned CaAlSiN3:Eu^(2+)phosphor-in-glass film–Y_(3)Al_(5)O_(12):Ce^(3+)phosphor-in-glass film@Al_(2)O_(3)plate with aluminum"heat sink")via a thermal management methodology of combining"phosphor wheel"and"heat sink"for a lighting source of highpower laser projection displays.This new composite design makes it effective to transport generated thermal phonons away to reduce the thermal ionization process,and to yield stable and high-quality white light with brightness of 4510 lm@43 W,luminous efficacy of 105 lm/W,correlated color temperature of 3541 K,and color rendering index of 80.0.Furthermore,the phosphor-in-glass film-converted laser projection system was also successfully designed,showing a more vivid color effect compared to a traditional LED-based projector.This work emphasizes the importance of the thermal management upon high-power laser irradiation,and hopefully facilitates the development of a new LD-driven lighting source for high-power laser projection displays.
基金This study is financially supported by the National Natural Science Foundation of China(grant no.21788102)the Natural Science Foundation of Guangdong Province(grant no.2019B030301003)the State Key Lab of Luminescent Materials and Devices,South China University of Technology。
文摘Constructing blue thermally activated delayedfluorescence materials for high-performance organic light-emitting diodes(OLEDs)remains challenging due to the intrinsically strong intramolecular charge transfer nature of the nearly orthogonal connection of electron donor(D)and acceptor(A),which results in long-wavelength emission.Herein,an effective delayed-fluorescence design strategy of modulating D–A torsion angles is proposed and efficient sky-blue,pure-blue,and deep-blue delayed-fluorescence molecules consisting of a xanthenone acceptor and carbazole-based donors are created by decreasing the torsion angles.They exhibit strong delayed fluorescence with high photoluminescence quantum yields of 85–94%in doped films,and their delayed-fluorescence lifetimes are elongated from 1.0 to 27.6μs as the torsion angles decrease.These molecules can function as excellent emitters in OLEDs,providing efficient electroluminescence peaking at 442 nm(CIEx,y=0.15,0.08),462 nm(CIEx,y=0.15,0.18),and 482 nm(CIEx,y=0.17,0.30)with state-of-the-art external quantum efficiencies of up to 22.2%,33.7%,and 32.1%,respectively,demonstrating the proposed molecular design for efficient blue delayed-fluorescence molecules is successful and promising.
基金National Natural Science Foundation of China,Grant/Award Numbers:51673084,21871108Jilin Province-University Cooperative Construction Project--Special Funds for New Materials,Grant/Award Number:SXGJSF2017-3。
文摘Aggregation-induced emission(AIE),as an exciting photophysical phenomenon,has been regarded as one frontier research topic within both ranges of molecular luminescence and materials science over the last two decades.Since controllable molecular ensembles with particular morphologies and tunable functions can be elegantly constructed in the realm of supramolecular chemistry,the integration of supramolecular assembly and AIE systems can expectedly bring about luminescent materials with tunable emission and tailorable well-ordered architectures.In this review,we will provide a summary of the creation and working mechanisms of AIE systems involving supramolecular systems that are driven by different supramolecular driving forces including hydrogen bonding,host−guest interactions,metal coordination,and π-π interactions.The morphological and photoluminescent features of these AIE-active supramolecular assemblies will be elucidated,and the regulated fluorescence properties of the AIEgens induced by the assembling-disassembling processes will be discussed in detail.
基金the National Natural Science Foundation of China(Nos.51902178,11804188,51702172,and 51802285)the Natural Science Foundation of Shandong Province(No.ZR201807060932)the Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology)(No.2019-skllmd-15)。
文摘To introduce ordered nano-structures inside a transparent amorphous matrix with superior optical and mechanical properties bears scientific and technological importance,yet limited success has been achieved.Here,via simple melting-quenching and subsequent thermal activation,we report the successful preparation of transparent nano-structured glass-ceramics embedded in Sr2Lu F7 nano-crystals(~26 nm),as evidenced by X-ray diffraction,transmission electron microscopy(TEM),and high resolution TEM.The successful incorporation of dopants into formed Sr2Lu F7 nano-crystals with low phonon energy results in highly tunable blue–green photoemission,which depends on excitation wavelength,dopant type,and temperature.We found that Eu3+and Eu2+ions co-exist in this hybrid optical material,accompanied by the broadband blue emission of Eu2+and sharp red emissions of Eu3+.A series of optical characterizations are summoned,including emission/excitation spectrum and decay curve measurement,to reveal the reduction mechanism of Eu3+to Eu2+.Furthermore,near green–white photoemission is achieved via the enrichment of Tb3+/Eu3+into crystallized Sr2Lu F7 nano-crystals.The temperature-dependent visible photoemission reveals thermal activation energy increases with the precipitation of Sr2Lu F7 nano-crystals in a glass matrix,suggesting better thermal stability of glass-ceramics than precursor glasses.These results could not only deepen the understanding of glass-ceramics but also indicate the promising potential of Eu3+/Tb3+-ions-doped Sr2Lu F7 glass-ceramics for UV pumped white light emitting diodes(WLEDs)with good thermal stability.
基金This work was supported by the NSFC(Nos.22071062,21871096,22001077)the Ministry of Science and Technology of the People's Republic of China(No.2016YFA0602900)+1 种基金Guangdong Science and Technology Department(Nos.2018B030308007,2021A1515012331)the China Postdoctoral Science Foundation(Nos.2018M643062,2019T120723).
文摘A highly efficient redox-and step-economic method to synthesize N,O-and O,O-difluoroboron complexes from alkynes under aqueous condition with HBF_(4) as BF_(2) source has been developed.This strategy features good yields,broad substrate scope,mild reaction conditions,readily available starting materials and gram-scale synthesis.Significantly,these difluoroboron complexes present good fluorescence properties,indicating their potential applications in luminescent materials.
文摘Forsterite particles doped with europium ions(Eu^(3+)) were synthesized via a solution combustion method. The effect of co-dopants on photoluminescence intensity was described. Different percentages of calcium(Ca^(2+)), zinc(Zn^(2+)), barium(Ba^(2+)) and strontium(Sr^(2+)) were added to the Mg_2SiO_4:Eu^(3+)host.The synthesized sample was characterized by X-ray diffraction, transmission electron microscopy,scanning electron microscopy, spectrofluorometer and the FTIR spectroscopy. X-ray diffraction(XRD)results revealed that dominant phase was forsterite in all samples. Additionally, a negligible amount of periclase phase was recognized in the samples. The average size of the synthesized particles was less than 200 nm. The presence of co-dopant led to an enhancement in the photoluminescent property of the synthesized samples. The maximum increase in photoluminescence intensity was obtained by Ba^(2+)ions as a co-dopant. Condensed films of photoluminescence particles were produced by utilizing electrophoresis technique to deposit particles. The results showed that polyvinyl pyrrolidone was the best surface modifier to raise the mass deposition of the samples on the substrate.
