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Crystal Structure and Luminescent Property of a One-Dimensional Chain Based on 1-(4-Nitrophenyl)-1,2,4-Triazole
摘要： A neutral one-dimensional CdII coordination polymer [Cd(NO2–BDC)(NPT)(H2O)2]n (1) (NO2–H2BDC=5-nitro-1,3-benzenedicarboxylic acid, NPT=1-(4-nitrophenyl)-1,2,4-triazole) is prepared and characterized through IR, elemental and thermal analyses, and single crystal X-ray diffraction. The single crystal X-ray diffraction analysis reveals that complex 1 is comprised of neutral 1D zigzag chains. The luminescence and thermal stability of complex 1 are investigated.
关键词： 1-(4-nitrophenyl)-1,2,4-triazole,one-dimensional chain,luminescence,coordination polymer,synthesis,5-nitro-1,3-benzenedicarboxylic acid
更新于2025-09-04 15:30:14
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Physicochemical Processes in the Synthesis of New Detectors of X-Ray Radiation Based on YAG:Ce-Halide Fluxes
摘要： Using the data of X-ray phase analysis, optical spectroscopy, and scanning electron microscopy of YAG:Ce luminophores, the main types of interactions in complex systems formed by a light-emitting diode luminophore and halide fluxing agents are determined, which cause intense luminescence in the ultraviolet region.
关键词： luminophores,UV luminescence,halide fluxes,YAG:Ce
更新于2025-09-04 15:30:14
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Photon Upconverted Circularly Polarized Luminescence via Triplet-Triplet Annihilation
摘要： Circularly polarized luminescent materials are of increasing attention due to their potential applications in advanced optical technologies, such as chiroptical devices and optical sensing. Recently, in all reported circularly polarized luminescent materials, high-energy excitation results in low-energy or downconverted circularly polarized luminescence (CPL) emission. Although photon upconversion—i.e., the conversion of low-energy light into higher-energy emission, with a wide variety of applications—has been widely reported, the integration of photon upconversion and CPL in one chiral system to achieve higher-energy CPL emission has never been reported. Herein, a brief review is provided of recent achievements in photon-upconverted CPL via the triplet–triplet annihilation mechanism, focusing on the amplified dissymmetry factor glum through energy transfer process and dual upconverted and downconverted CPL emission through chirality and energy transfer process.
关键词： triplet–triplet annihilation,photon upconversion,energy transfer,triplet energy migration,circularly polarized luminescence
更新于2025-09-04 15:30:14
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Synthesis and luminescence properties of Eu3+-doped a novel double perovskite Sr2YTaO6 phosphor
摘要： A novel Sr2Y1?xTaO6:xEu3+ (x = 0.04–0.20) red-emitting phosphor was synthesized by using the conventional solid-state reaction method. The crystal structure, photoluminescence properties, thermal stability and decay lifetimes were investigated in detail. Upon near UV light excitation, this sample exhibited a strong red emission peak centered at 612?nm due to 5D0 → 7F2, which indicated that Eu3+ occupies low symmetry sites within the Sr2YTaO6 host lattice. The optimized doping concentration of Eu3+ ion is about 12?mol%. The excellent thermal stability of Sr2YTaO6:Eu3+ phosphor was tested according to the temperature dependent emission spectra. In addition, the Sr2Y1?xEuxTaO6 phosphors exhibited good color coordinate (0.6076, 0.3879) and high color purity about 84.55%. All results indicated that the Sr2Y1?xTaO6:xEu3+ phosphors can serve as an efficient red phosphor in the white light emitting diodes.
关键词： Sr2YTaO6:Eu3+,phosphor,luminescence,thermal stability,white light emitting diodes
更新于2025-09-04 15:30:14
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Board‐like Fused‐Thiophene Liquid Crystals and Their Benzene Analogues: Facile Synthesis, Self‐assembly, p‐Type Semiconductivity, and Photoluminescence
摘要： Novel fused-thiophene discotic liquid crystals were designed and easily synthesized by Suzuki coupling and FeCl3 oxidized tandem cyclo-dehydrogenation reactions, including homo- and cross-coupling reactions. The resulting hexagonal and rectangular columnar mesomorphic supramolecular structures formed were characterized by polarizing optical microscopy, differential scanning calorimetry, and small-angle X-ray scattering. Charge carrier transport properties in the mesophases of two of the synthesized fused-thiophene discogens were measured by transient photocurrent time-of-flight (TOF) technique, revealing fast hole transport values in the range of 10-3 to 10-2 cm2 V-1s-1, thus demonstrating potential applications in electronic devices. The luminescent sanidic mesogens, having different extended π-conjugated systems, also emit blue, green or red light, with absolute photoluminescent quantum yields as high as 18%.
关键词： thiophene,luminescence,mesophase,cyclo-hydrogenation,charge mobility
更新于2025-09-04 15:30:14
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Effects of Al3+ substitution on the luminescence properties of LuNbO4 doped with Eu3+ and Tb3+ ions
摘要： The effect of Al3+ substitution on the enhancement of the luminescence of Lu1–xAlxNbO4:Eu3+ and Lu1–xAlxNbO4:Tb3+ was investigated. X-ray diffraction patterns confirmed that the Eu3+, Tb3+, and Al3+ ions were fully incorporated into the Lu3+ sites. In the case of Lu1–xAlxNbO4:Eu3+, the predominant red emission (614 nm) was assigned to the 5D0 → 7F2 transition of Eu3+ and for x = 0–0.05, its intensity increased up to ~125 and 108% under 395 nm (7F0 → 5L6) and a charge transfer band excitation, respectively. For Lu1–xAlxNbO4:Tb3+, the strongest emission band peaking at 551 nm was attained in the green region among multiple emission bands corresponding to the 5D4 → 7FJ transitions of Tb3+. Increasing the x values from 0 to 0.05 increased the green emission significantly by ~137%. These phenomena were explained by the local structural distortions and crystal field asymmetry surrounding Eu3+ and Tb3+, which were attributed to a large difference in the ionic radii of Al3+ and Lu3+.
关键词： Terbium,Luminescence,Europium,Phosphor,Lutetium niobate
更新于2025-09-04 15:30:14
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Synthesis, energy transfer, charge compensation and luminescence properties of CaZrO3:Eu3+, Bi3+, Li+ phosphor
摘要： A series of CaZrO3:Bi3+, CaZrO3:Eu3+, CaZrO3:Eu3+, Bi3+, and CaZrO3:Eu3+, Bi3+, Li+ phosphors are synthesized by high-temperature solid-state reaction method in air. Their luminescence properties are researched, compared, and analyzed. CaZrO3:Bi3+ phosphor under excitation at 310?nm emits deep-blue light with chromaticity coordinate (0.1612, 0.0254). CaZrO3:Eu3+ phosphor under excitation at 310 and 395?nm shows red-emitting with chromaticity coordinate (0.6386, 0.3611). CaZrO3:Eu3+, Bi3+ phosphor under excitation at 310?nm exhibits a systematically varied hue from deep-blue to red light by changing Eu3+ ion concentration, and that with excitation at 395?nm only emits red light with chromaticity coordinate (0.6386, 0.3611). The energy transfer process from Bi3+ to Eu3+ ions may be indicated by their spectral properties. The optimal Eu3+ and Bi3+ ions concentrations are 5?mol% and 0.9?mol%, respectively. The emission intensity CaZrO3:Eu3+, Bi3+ phosphor may be enhanced about 1.6 times due to the co-doping Li+ ion as charge compensator role. The luminous mechanism of CaZrO3:Eu3+, Bi3+ phosphor is explained by the simplified energy level diagrams of Bi3+ and Eu3+ ions.
关键词： energy transfer,CaZrO3,luminescence,charge compensation,phosphor
更新于2025-09-04 15:30:14
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High-temperature high pressure synthesis of monoclinic Y2O3
摘要： In this work, synthesis of cubic Y2O3 by calcining yttrium based coordination polymer (Y-CP) which were obtained by microwave-assisted method was reported. Monoclinic Y2O3 was obtained by treating the cubic Y2O3 under high temperature high pressure (HTHP) on a large volume cubic multi-anvil high pressure apparatus. The effect of temperature on the preparation was studied. The morphology and crystal phase of all samples have been characterized by the scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) spectra. What more, the photoluminescence (PL) property of the Y2O3: Eu3+ sample was investigated. This method can be used to prepare other rare earth oxide with various phase.
关键词： Coordination polymer,luminescence,Y2O3,high temperature high pressure,Phase transformation
更新于2025-09-04 15:30:14
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Hydrothermal Approach to Spinel-Type 2D Metal Oxide Nanosheets
摘要： The peculiar physical and chemical properties of 2D nanostructures have aroused global research interest in developing new members, synthetic technology, and exploring their potential applications in functional nanodevices. However, it is extremely challenging to directly obtain the 2D nanosheets for these extrinsic layered structures using conventional routines. In this work, we demonstrate the facile and general synthesis of 2D spinel-type metal oxides nanosheets through a simple hydrothermal reaction. Using this method, cubic γ-Ga2O3, ZnGa2O4 and MnGa2O4 nanosheets with triangular/hexagonal configuration and ultrathin thickness have been synthesized, and all these nanosheets show preferential growth along (111) plane with the minimum formation energy. Microstructural and composition analyses using HRTEM, EDS, XPS, and so on reveal that the as-synthesized 2D nanosheets are well-crystallized in cubic fcc-phase and show high purity in composition, and the formation process of MGa2O4 nanosheets can be regarded as the competition of M2+ and Ga3+ in tetrahedral site. Spatially resolved cathodoluminescence measurement of individual 2D nanosheet shows that the γ-Ga2O3, ZnGa2O4, and MnGa2O4 nanosheets exhibit distinct luminescence behavior, and ZnGa2O4 nanosheets show the strongest emission in visible region. It is expected that the facile synthesis of spinel-type metal oxides of γ-Ga2O3, ZnGa2O4, and MnGa2O4 nanosheets will further promote the exploration of a variety of semiconductor nanostructures that could not be achieved using conventional technology suitable for layered structures and will also open up some opportunities for the integration of advanced functional nanodevices such as photodetectors, phosphors on the basis of them.
关键词： spinel-type metal oxides,functional nanodevices,2D nanostructures,luminescence behavior,hydrothermal reaction
更新于2025-09-04 15:30:14
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Wide-Range UV-to-Visible Excitation of Near-Infrared Emission and Slow Magnetic Relaxation in Ln <sup>III</sup> (4,4′-Azopyridine-1,1′-dioxide)[Co <sup>III</sup> (CN) <sub/>6</sub> ] <sup>3–</sup> Layered Frameworks
摘要： Trivalent lanthanide ions combined with two linkers, organic 4,4′-azopyridine-1,1′-dioxide (apdo), and inorganic hexacyanidocobaltate(III), gave a series of magnetoluminescent coordination polymers, [{LnIII(apdo)(H2O)4}{CoIII(CN)6}]·2H2O (Ln = Nd, 1; Tb, 2; Dy, 3; Er, 4; Tm, 5; Yb, 6). They are hybrid organic?inorganic layered frameworks composed of cyanido-bridged {Ln2(μ-NC)4Co2} squares linked by Ln?apdo?Ln bridges into a coordination network of a mixed 4- and 8-metal ring topology. Lanthanide(III) complexes, [LnIII(μ-apdo)2(H2O)4(μ-NC)2]+, of a distorted dodecahedral geometry are isolated by diamagnetic [CoIII(CN)6]3? and apdo linkers. As a result, 1?6 reveal field-induced slow relaxation of magnetization, with typical temperature-dependent relaxation of a single-ion origin for NdIII-containing 1, DyIII-containing 3, and YbIII-containing 6. The related alternate-current magnetic data were precisely analyzed, indicating the multiple magnetic relaxation pathways, including a direct process, strong quantum tunneling of magnetization, non-negligible Raman processes, and crucial two-phonon Orbach thermal relaxation. The thermal energy barriers of the Orbach process, ΔE/kB, are 15.1(9) K with τ0 = 9.8(9) × 10?6 s at Hdc = 4500 Oe, 16.1(8) K with τ0 = 9.0(9) × 10?5 s at Hdc = 1500 Oe, and 17.3(6) K with τ0 = 3.2(7) × 10?6 s at Hdc = 700 Oe, for 1, 3, and 6, respectively, proving the single-molecule magnet (SMM) behavior. Because of the presence of [Co(CN)6]3?, 1?6 show strong UV absorption, while the chromophoric apdo leads to the strong absorption in the visible range. As a result, the visible 4f/3d metal-centered emission is quenched, but the near-infrared luminescence from NdIII and YbIII is observed in 1 and 6, respectively. It is realized by Co-to-Ln metal-to-metal, and apdo-to-Ln ligand-to-metal energy transfers; thus, broad UV-to-visible excitation can be explored. Compounds 1?6 form a novel family of functional bimetallic assemblies, incorporating NIR-emissive SMMs as presented for NdCo (1) and YbCo (6) derivatives.
关键词： single-molecule magnets,near-infrared luminescence,coordination polymers,magnetoluminescent,lanthanide
更新于2025-09-04 15:30:14