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White light emitting thermally stable bismuth phosphate phosphor Ca <sub/>3</sub> Bi( <scp>PO</scp><sub/>4</sub> ) <sub/>3</sub> :Dy <sup>3+</sup> for solid state lighting applications
摘要： White light emitting dysprosium doped Ca3Bi(PO4)3 phosphor was successfully synthesized via co-precipitation method for the first time and the structural, vibrational, morphological and luminescent properties have been investigated for solid state lighting applications. The X-ray diffraction (XRD) and structural refinement studies reveal that the synthesized phosphors consist of single phase with cubic structure. The field emission scanning electron microscopy (FE-SEM) images reveal that the as-synthesized phosphor has micron size with an irregular shape. Under near ultraviolet (n-UV) and blue excitation, the phosphor exhibits white light emission via a combination of blue (~451 nm) and yellow (~575 nm) emission bands. The optimized concentration of Dy3+ ions is 6.0 mol % after which the concertation quenching takes place. The process of energy transfer between Dy3+ ions is due to dipole-dipole interaction, which was confirmed by applying Dexter and Reisfeld’s Energy Transfer (ET) formula. The CIE chromaticity coordinates for the optimized phosphor were (0.329, 0.377), which lie in the white light region. The emission intensity remains to 83.41% at 373 K to that of at room temperature, which indicates good thermal stability. The above mentioned results demonstrate that Ca3Bi(PO4)3 is a potential phosphor for solid state lighting applications.
关键词： White LEDs,Structural and luminescent properties,White light emission,Phosphor,Thermally stable
更新于2025-11-21 11:18:25
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Luminescent Mesoporous Silica Nanohybrid Based on Drug Derivative Terbium Complex
摘要： Mesoporous silica nanoparticles prepared by organic template-driven synthesis have been successfully explored as carriers of the drug-derivate green luminescent complex of terbium (III) with the nonsteroidal anti-inflammatory drug ketoprofen. The terbium (III) complex was synthesized by reacting ketoprofen sodium salt with terbium (III) chloride, which was further adsorbed onto the surface of mesoporous nanoparticles with a mean particle size of 47 ± 4 nm and pore size of 11 nm. The incorporation of the complex into mesoporous silica nanoparticles was tracked by the decrease in the surface area and pore size of the nanoparticles, and successfully demonstrated by substantial changes in the adsorption isotherms and thermal and vibrational spectroscopy results. The cytotoxicity assay and confocal microscopy have shown that the novel luminescent nanohybrid presents high cell viability and the characteristic terbium (III) emission can be assessed through two-photon excitation, which paves the way for bioimaging applications in nanomedicine.
关键词： ketoprofen,mesoporous silica nanoparticles,terbium,luminescent nanohybrid,two-photon
更新于2025-11-21 11:08:12
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Silicon nanowire luminescent sensor for cardiovascular risk in saliva
摘要： Cardiovascular diseases are some of the today major cause of death in the world. C-reactive protein (CRP) is well known as the main biomarker related to cardiovascular risk and heart attack occurrence. The standard CRP analyses are performed in a hospital or in a biochemical laboratory with blood analysis after a long chemical and labelling preparation that require expert personnel. In this scenario, a health care analysis that can be performed by the same patient at his own home appears extremely revolutionary. In this paper, the study of an innovative sensing platform based on the luminescence at room temperature of silicon nanowires (NWs) is reported. This NWs sensor is label-free and does not require a chemical treatment of the analyte, is strongly selective to the CRP demonstrating a femtomolar limit of detection and a wide operating range. This proposed silicon sensing platform can be realized with an industrial compatible approach and permits to reveal the strategic CRP level in saliva in order to prevent a heart attack, with great advantages for the patient.
关键词： Cardiovascular risk,Saliva,C-reactive protein,Silicon nanowires,Luminescent sensor
更新于2025-11-21 11:01:37
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Synthesis, energy transfer and multicolor luminescent property of Eu3+-doped LiCa2Mg2V3O12 phosphors for warm white light-emitting diodes
摘要： In this study, Eu3+-doped LiCa2Mg2V3O12 (LCMVO) phosphors with multicolor luminescent property were prepared by the solid phase reaction. Their structure, morphology and luminescent property were studied systematically by X-ray diffraction, scanning electron microscope and photoluminescence spectra. The LCMVO phosphors showed pure cubic crystal structure with space group (3Ia d ) and irregular spherical morphology. The excitation spectra showed a strong absorption to ultraviolet light. Under the excitation wavelength at 360 nm, they exhibited a cyan emission with a luminescence center at 520 nm. When Eu3+ ions were doped into LCMVO system, the Eu3+ characteristic emissions were also observed and the emission colors were tuned from cyan to orange via adjusting Eu3+ ion concentration. Further, electric dipole-quadrupole interaction and luminescence decay curves were adopted to explain the energy transfer from (VO4)3- to Eu3+. The emission spectra of as-obtained phosphors at different temperature were measured to evaluate their thermal stability. The quantum efficiency values were measured to be 42.5% for LCMVO host and 38.6% for LCMVO: 0.01Eu3+ sample. The final prepared LED lamp showed easeful warm white light with suitable Ra of 89 and CCT of 3847 K, respectively. These results suggest LCMVO phosphors may be applied in near ultraviolet chip-excited white light-emitting diodes.
关键词： energy transfer,multicolor luminescent,self-activated luminescence,excitation and emission spectra,vanadate phosphor,UV-LED
更新于2025-11-20 15:33:11
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Dual-mode luminescent core-shell nanoarchitectures for highly sensitive optical nanothermometry
摘要： Currently, FIR-based luminescent nanothermometry has aroused wide concern for its promising applications in fast-moving objects, harsh environments and microscopic temperature. Synchronously promoting the absolute and relative sensitivities of optical thermometers is one of the significant issues at present. In this work, a new nanothermometry strategy to possess both high absolute and relative sensitivities have been proposed by coupling of thermally-coupled-levels-based technique with non-thermally-coupled-levels method in the core-shell designed nanomaterials. Following this strategy, the core-shell-structured NaGdF4:Yb,Er@ NaYF4:Ce,Tb,Eu nanocrystals have been successfully prepared. Remarkably, the adverse cross-relaxation among different activators is extremely suppressed owing to the spatial separation of Er3+ and Eu3+/Tb3+ activators, being conducive to the realization of both intense green upconverting emissions and yellow downshifting luminescence. Moreover, the temperature-sensitive dual-mode luminescent behaviors of core-shell nanomaterials are systematically studied to probe the possible application in FIR-related luminescent thermometry. Specially, the thermally-coupled-levels-based FIR of Er3+ : 2H11/2 / 4I15/2 to Er3+ : 4S3/2 / 4I15/2 and non-thermally-coupled-levels-based FIR of Eu3+ : 5D0 / 7F2 to Tb3+ : 5D4 / 7F6 are proved to be applicable as temperature probes, leading to the achievement of dual-mode temperature sensing. Using the pre-designed core@shell nanoarchitectures, the absolute sensitivity can reach up to 1.02% K-1 based on Eu3+/Tb3+ Stokes emissions and the relative sensitivity could reach as high as 1.12% K-1 based on Er3+ anti-Stokes luminescence. We believe that this study provides a valid approach for developing high-performance optical nanothermometers.
关键词： Optical nanothermometry,Rare-earth luminescent materials,Dual-mode emission,Core-shell nanoarchitectures
更新于2025-11-20 15:33:11
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Highly selective detection of Fe3+, Cd2+ and CH2Cl2 based on a fluorescent Zn-MOF with azine-decorated pores
摘要： The design and synthesis of sensitive and selective luminescent materials as chemical sensing agents is a fundamental goal in fluorescence assays. Considering high porosity, large surface area, excellent photoluminescence property of metal-organic frameworks (MOFs), luminescent properties of a microporous azine-functionalized MOF, TMU-16, dispersed in different metal ions and solvents have been investigated systematically. The TMU-16 displays superb luminescence emission, and it can detect Fe(III) and Cd(II) ions with high selectivity, excellent sensitivity, and short response time (<1 min). The emission intensities of TMU-16 were quenched upon the addition of Fe3+ and increased upon the addition of Cd2+. The detection limits of TMU-16 for Fe3+/Cd2+ in DMF are estimated to be 0.2 and 0.5 μM, respectively. The effect of other metal ions on the fluorescence intensity of the MOF was also studied and other metal ions showed low interference response in recognition of Fe3+ and Cd2+. Furthermore, TMU-16 exhibits distinct solvent-dependent luminescent spectra with emission intensity significantly enhanced toward dichloromethane. More importantly, this is the first example of MOF-based luminescent sensor as efficient multifunctional fluorescence material which can use for selective sensing of Fe(III) and Cd(II) ions and small molecules such as CH2Cl2.
关键词： Small molecules,Metal ions,Luminescent,Sensing,Metal-organic frameworks,Detection
更新于2025-11-19 16:46:39
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Bulk luminescent solar concentrators based on organic-inorganic CH3NH3PbBr3 perovskite fluorophores
摘要： In this paper, we report characterization and performance results of lead bromide perovskite luminescent solar concentrator. CH3NH3PbBr3 fluorophores are synthesized by sonication method and examined by their X-ray diffraction pattern and scanning electron microscopy. Synthesized perovskite shows excitonic absorption at 524 nm and PL emission peak located at 532 nm with a Stokes shift around 8 nm. Micron-sized fluorophores are dissolved in prepared solutions and uniformly embedded in PMMA host with 0.006–0.120%wt concentration. Then, Fabricated devices are cut into 50 × 30 × 5 mm cuboid shapes and placed in a mirror surrounded configuration with an attached photovoltaic cell. Fabricated device is put under standard AM1.5 illumination and the output spectrum from the concentrator is acquired. Re-absorption in the samples is also measured by variable optical path method, showing red-shifts up to 13 nm in the output spectrum. Spatially resolved photo-luminescence maps and optical efficiencies are also presented for each sample. Plus, a Monte-Carlo ray tracing algorithm is developed to assist better understanding the experimental results. Stability of fabricated samples are evaluated under high intensity UV illumination, reporting efficiency reduction around 15% after 24 h. Finally, Comparing current-voltage characterization of the attached photovoltaic cell reveals optimized efficiency enhancement in the 0.04%wt sample above 65%.
关键词： Perovskites,Monte-Carlo simulation,Re-absorption,Luminescent solar concentrators,Photovoltaic conversion efficiency,Solar cells
更新于2025-11-14 15:30:11
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Luminescent Composites Based on Tetrafluoroethylene Copolymer Porous Films Produced by the Diffusion Embedding of Semiconductor Nanoparticles in a Supercritical Medium
摘要： A method for creating film composites based on a new material—a fibrous copolymer of tetrafluoroethylene and vinylidene fluoride—using the diffusion embedding of ready-made nanoparticles into a porous matrix in a supercritical (SC) carbon dioxide medium is developed. The method of cold or hot pressing of impregnated porous films was used at the final stage of creation of such composites. The peculiarities of the effect of the supercritical fluid treatment of porous copolymer films on the surface structure of pressed films are discussed. Luminescent composites with semiconductor nanoparticles of cadmium selenide and nanocrystalline silicon are obtained; their radiation covers a range of 500–1000 nm. The change in the luminescence properties of the resulting nanocomposites under the action of excitation laser radiation at 405 nm is demonstrated.
关键词： cadmium selenide,film composite,fibrous matrix,luminescent properties,diffusion embedding,nanocrystalline silicon
更新于2025-11-14 15:30:11
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Synthesis of luminescent polymers in the UV light region from dimethacrylate monomer using novel quinoline dyes
摘要： This study aims at thermal and morphological features, as well as the degree of conversion these luminescent polymers obtained using a dimethacrylate monomer, and quinoline dyes as photoinitiator. The photoinitiators provide a ?uorescent propriety to the ?nal polymer. Thermal properties such as thermal stability, steps of mass loss, and glass transition are obtained by thermogravimetry-differential thermal analysis and derivative thermogravimetric and differential scanning calorimetry. Using the mid-infrared spectroscopy, it is possible to calculate the degree of conversion/rate of polymerization; the data indicate that the quinoline derivatives could be used as photoinitiators in lower concentration (0.1%) resulting in solid rigid polymers with higher conversion (74.24, 71.81, 66.36, and 61.09%). The morphological characteristics of polymers are analyzed by scanning electronic microscopy. Finally, solid ultraviolet–visible (UV–vis) analysis shows a bathochromic shift, due to the stabilization of the molecules in the solid state, compared to liquid UV–vis analysis. ? 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47461.
关键词： thermal analysis,quinoline dyes,photopolymerization,luminescent polymers,high conversion
更新于2025-11-14 15:18:02
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Luminescent materials of covalent grafting lanthanide complexes to the synthetic clays
摘要： Lanthanide complex-based luminescent organic-inorganic hybrid materials are highly interesting for a broad range of application fields. The combination of lanthanide complexes with the synthetic clay, Laponite, is now attracting the interest of scientists due to the unique features of the synthetic clay. However, most of the reported literatures are involved with the adsorption of lanthanide complexes on the clay particles. Taking the covalent incorporation of lanthanide complex into clay and satisfying the further coordinate with central lanthanide ion into account, herein, we reported a facile strategy of covalent grafting lanthanide complexes to the clay via the reaction of the terminal triethoxy groups of triethoxysilylated ligand (phenSi) and the surface OH groups of the clay. The successful grafting of the complexes was confirmed by the FT-IR spectra, 29Si solid-state NMR spectra and the luminescent data. And the nitrogen atoms of Phen moieties which are covalently grafted to the clay provide the chance to prepare luminescent hybrid materials with larger coordination number.
关键词： covalent grafting,lanthanide complexes,Laponite,luminescent materials
更新于2025-11-14 15:18:02