- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Tunable magnetic and fluorescent properties of Tb3Ga5O12 nanoparticles doped with Er3+, Yb3+, and Sc3+
摘要： In this study, we present the synthesis of Tb3Ga5O12 nanoparticles doped with Er3+, Yb3+, and Sc3+ ions, prepared using a co-precipitation method. These materials have well-defined magnetic-fluorescence properties. The effects of Yb3+ ion concentration on the structural characteristics, morphology, luminescence, and magnetic properties of the nanoparticles were investigated in detail using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, photoluminescence spectroscopy, and vibrating sample magnetometer measurements. Under 980-nm laser diode excitation, the nanoparticles displayed bright up-conversion luminescence, showing evidence of resonant energy transfer from the Yb3+ to Er3+ ions. Intense green and red emissions located at approximately 526, 548, and 656 nm were attributed to the radiant transitions of 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4F9/2 → 4I15/2 of Er3+, respectively. These observations indicate that Tb3Ga5O12:Er3+, Yb3+, Sc3+ magnetic–fluorescent bifunctional nanoparticles are promising materials for use in bioimaging and magnetic bio-separation applications.
关键词： magnetic properties,lanthanide-doped materials,nanoparticles,rare-earth metal,terbium gallium garnet (Tb3Ga5O12),up-conversion luminescence
更新于2025-11-14 15:26:12
-
Synthesis of near unity photoluminescence CdSeTe alloyed Quantum Dots
摘要： Quantum dots (QD) tend to exhibit low photoluminescence (PL) properties due to long hanging ligands on their surface and steric barriers resulting therefrom. On the other hand, in order to be used in QD LED and QDSSC technologies, highly intense PL characteristics and PL lifetime are required respectively. Therefore, this study focuses on increasing the PL QY and PL lifetime of CdSeTe alloy QDs. To achieve this aim, CdSeTe alloy QDs synthesized by organometallic method were treated with different mass % (m/m) chloride solution. The PL Quantum Yield (PL QY) of CdSeTe alloy QDs, which was 13.2 ± 2.0% before treatment, increased to 97.4 ± 2.0% after treatment with 60% CdCl2 solution approaching to almost unity value. In addition to the increase in PL QY, PL lifetime increased from 28 ns to 33 ns with chloride treatment. However, thanks to surface passivation, the time to fall to half the value of PL QY for treated CdSeTe(Cl) QDs under oxygen exposure was increased from 10 h to 64 h. In the study, the absorbance and emission characterizations of CdSeTe alloy QDs treated with chloride and untreated, were presented.
关键词： Quantum dot,Photo luminescence,CdSeTe,Chloride treatment,Quantum yield
更新于2025-11-14 15:24:45
-
Eu and Dy doped borophosphosilicate glass-ceramics for near ultraviolet based light-emitting diode applications
摘要： The Eu and Dy doped borophosphosilicate glass-ceramics prepared using melt quenching technique are investigated for light-emitting diode applications. The X-ray diffraction results show that the precipitation of AlPO4 crystals in glass matrix occurred during the melt quenching process, leading to the formation of glass-ceramics. The content of AlPO4 crystals depends on the B2O3/P2O5 relative content in glass matrix composition. The spontaneous conversion of Eu3+ to Eu2+ takes place in the as-obtained glass-ceramics without using reducing atmosphere during the preparation process. The conversion extent of Eu3+ to Eu2+, optical properties and structure of the as-obtained materials are related to the B2O3/P2O5 relative content. The Eu/Dy co-doped borophosphosilicate glass-ceramics display the emission bands in the blue, yellow, and red light regions and their combinations generate near white light-emission. In addition, the tunable light emission can be realized by changing the concentration of Eu and B2O3/P2O5 relative content. The as-developed Eu and Dy doped borophosphosilicate glass-ceramics show promising prospects in light-emitting diode applications.
关键词： Rare earth,Luminescence,Light-emitting diode,Borophosphosilicate glass-ceramics
更新于2025-11-14 15:23:50
-
Ammonia-Responsive Luminescence of Ln3+-β-diketonate Complex Encapsulated within Zeolite Y
摘要： Assembling Ln3+(HPBAn) (Ln = Eu or Tb, HPBA = N-(2-pyridinyl)benzoylacetamide) in the cavities of zeolite Y (ZY) via the “ship-in-a-bottle” strategy leads to the formation of novel luminescent composite, Ln(HPBAn)@ZY, whose luminescence can be easily modulated by ammonia on the basis of the energy level variation of HPBA after deprotonation process. Additionally the bimetallic complex doping sample, Eu0.5Tb0.5(HPBAn)@ZY, show great potential as self-referencing luminescent sensor for detecting low ammonia concentration of 10?12–0.25 wt%.
关键词： zeolite Y,luminescence,Ln3+-β-diketonate complex,ammonia-responsive
更新于2025-11-14 15:18:02
-
Synthesis, crystal structure and fluorescent sensing property of metal-organic frameworks with 1,3-di(1H-imidazol-4-yl)benzene and 1,4-phenylenediacetate
摘要： In this work, two new metal–organic frameworks (MOFs) based on 1,3-di(1H-imidazol-4-yl)benzene (L) and 1,4-phenylenediacetic acid (H2pda), namely [Ni(L)(pda)(H2O)] (1) and [Cd(L)(pda)] (2), have been achieved. MOFs 1 and 2 have distinct infinite one-dimensional (1D) chain structures, which are further linked together by hydrogen bonding interactions to give the eventual three-dimensional (3D) supramolecular architectures. Photoluminescence studies revealed that the Cd(II) MOF 2 shows strong emission at 346 nm upon excitation at 308 nm at room temperature. Furthermore, 2 can efficiently detecting acetone molecules, and Fe3+ and Cr2O7 2- ions via fluorescent quenching.
关键词： Acetone,Ions,Metal-organic frameworks,Detection,Luminescence
更新于2025-11-14 15:18:02
-
Energy Transfer from Ce3+ to Tb3+ in Yttrium and Gadolinium Orthoborates Obtained by Hydrothermal Synthesis
摘要： We studied the structure, IR absorption spectra, the spectral characteristics of photoluminescence and morphology of cerium- and terbium-doped orthoborates of gadolinium and yttrium obtained by hydrothermal synthesis at 200°C, as well as solid solutions of orthoborates on the basis of yttrium, gadolinium, and lutetium with composition RECe0.01Tb0.1BO3 (RE = Lu0.5Gd0.39, Lu0.5Y0.39, and Y0.5Gd0.39). The X-ray diffraction spectrum of yttrium orthoborate Y1 – x – yCexTbyBO3 is described by a hexagonal lattice with space group P63/m, which, after annealing at 970°C, transforms into a monoclinic lattice with space group C2/c. High-temperature annealing of the studied orthoborates leads to a multiple, more than two orders of magnitude, increase in the luminescence intensity of Tb3+ ions when the samples are excited in the absorption band of cerium ions. This effect is the result of a significant increase in the concentration of Ce3+ ions in the orthoborates at high temperatures. It is shown that the luminescence of terbium ions is due to energy transfer from Ce3+ to Tb3+, which proceeds with high efficiency (～85%) by the mechanism of dipole-dipole interaction between cerium and terbium.
关键词： orthoborates,luminescence,Ce3+,hydrothermal synthesis,energy transfer,Tb3+
更新于2025-11-14 15:14:40
-
A novel orange–red emitting phosphor Sr2LuTaO6:Sm3+ for WLEDs
摘要： A novel double perovskite tantalite orange–red light emitting Sr2LuTaO6:Sm3+ phosphor was synthesized by the solid state reaction. The phase, crystal structure, photoluminescence properties, thermal stability and decay curves were studied. The X-ray diffraction patterns indicated that the phosphor has a pure phase of cubic phase structure. Excited by near-ultraviolet light at 407 nm, the sample exhibited three sharp emission peaks at 564 nm, 600 nm, 645 nm corresponding to the 4G5/2 → 6HJ (J = 5/2, 7/2 and 9/2) transitions, respectively. The optimum doping concentration of Sm3+ ions was determined to be 5 mol% and the concentration quenching process comes from the energy transfer among nearest-neighbor ions. The as-prepared phosphors showed excellent thermal stability, the integral intensity at 423 K is about 91.10% of the initial intensity. The CIE chromaticity coordinates of Sr2LuTaO6:Sm3+ phosphors located in orange–red region. The results suggest that Sr2LuTaO6:Sm3+ phosphors have great potential application in white light-emitting diodes.
关键词： luminescence,thermal stability,white light-emitting diodes,Sr2LuTaO6:Sm3+,phosphor
更新于2025-11-14 15:13:28
-
Luminescence properties of novel Eu <sup>3+</sup> ‐doped tantalate NaCaTiTaO <sub/>6</sub> red‐emitting phosphors for solid‐state lighting
摘要： A novel tantalate red-emitting phosphors NaCa1-xEuxTiTaO6 (x = 0.02-0.50) is synthesized via the traditional solid-state reaction sintering. The photoluminescence properties, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermal stability are characterized in detail. Photoluminescence spectra show strong red emission monitored at 614 nm at λex = 395 nm. The spectral properties exhibit excellent color purity, chromaticity coordinate (CIE) characteristics. White light emitting diodes (w-LEDs) device are fabricated by the prepared phosphors and show high quality of color-rendering index. The investigated results suggest that the Eu3+-doped NaCaTiTaO6 phosphors can be as potential substitute red phosphors for w-LEDs.
关键词： Phosphors,Tantalate,NaCaTiTaO6:Eu3+,Luminescence
更新于2025-11-14 15:13:28
-
Anisotropic infrared light emission from quasi-one-dimensional layered TiS<sub>3</sub>
摘要： Atomically thin semiconductors hold great potential for nanoscale photonic and optoelectronic devices because of their strong light absorption and emission. Despite progress, their application in integrated photonics is hindered particularly by a lack of stable layered semiconductors emitting in the infrared part of the electromagnetic spectrum. Here we show that titanium trisulfide (TiS3), a layered van der Waals material consisting of quasi-one-dimensional chains, emits near infrared light centered around 0.91 eV (1360 nm). Its photoluminescence exhibits linear polarization anisotropy and an emission lifetime of 210 ps. At low temperature, we distinguish two spectral contributions with opposite linear polarizations attributed to excitons and defects. Moreover, the dependence on excitation power and temperature suggests that free and bound excitons dominate the excitonic emission at high and low temperatures, respectively. Our results demonstrate the promising properties of TiS3 as a stable semiconductor for optoelectronic and nanophotonic devices operating at telecommunication wavelengths.
关键词： infrared luminescence,transition metal trichalcogenides,titanium trisulfide,linear polarization anisotropy,layered semiconductors
更新于2025-11-14 14:32:36
-
Observation of strong thermally transferred optically stimulated luminescence (TT-OSL) in BeO
摘要： This work reports the observation of strong thermally transferred optically stimulated luminescence (TT-OSL) signal of BeO OSL ceramic detectors. If the detector is irradiated and the OSL signal is measured for a prolonged time (bleached), subsequent OSL measurements result in zero signal. If the same detector, however, is heated to temperatures in the 225 – 335 °C range (at 5 °C/s), subsequent OSL measurements at room temperature result in an intense signal, even without additional irradiation. The TT-OSL is maximum for a pre-heating to 275 °C (if heated linearly at 5 °C/s), reaching a value of 56 % of the original OSL signal. Both OSL and TT-OSL are reproducible (~3 % standard deviation) and linear with dose over the dose range investigated (up to 100 mGy). The shape of the OSL and TT-OSL curves are essentially identical. A possible explanation for this phenomenon is the thermally stimulated transfer of trapped charges from optically inactive traps to optically active traps responsible for the OSL signal. Correlation between the OSL, TT-OSL and the thermoluminescence (TL) peaks suggests the trapping centers associated with the TL peak at ~310 °C/s (at 5 °C/s) as the source of the trapped charges. These results have implication for the re-estimation of the OSL signal in BeO detectors accidentally exposed to light. Not only they provide further evidence that the material is not completely reset simply by bleaching (optical stimulation), but open a new line of investigation into the underlying TL/OSL mechanisms in BeO.
关键词： thermoluminescence,optically stimulated luminescence,BeO,thermally transferred optically stimulated luminescence,luminescence dosimetry,recuperation
更新于2025-09-23 15:23:52