Characteristic Emission Of Tb3 Research Articles

Yb3+-Doped Two-Dimensional Upconverting Tb-MOF Nanosheets with Luminescence Sensing Properties.

In this article, we synthesized a Yb3+-doped two-dimensional (2-D) upconverting Tb metal-organic framework (Tb-MOF) (hereinafter referred to as Tb-UCMOF) by a one-step solvothermal method. The synthesized Tb-UCMOF is composed of stacks of 2-D nanosheets with an average width distributed between 250 and 300 nm, and these nanosheets can be exfoliated by a simple liquid ultrasound method. The structural characteristics of this flaky particle accumulation are confirmed by the type IV adsorption-desorption isotherm with a H3-type adsorption hysteresis loop, and the Brunauer-Emmett-Teller surface of Tb-UCMOF is 143.9257 m2·g-1. Tb-UCMOF has characteristic emissions of Tb3+ which are located at 490, 545, 585, and 621 nm under 980 nm excitation. The upconverting luminescence mechanism is attributed to that Yb3+ absorbs multiple photons and transfers the energy to Tb3+, causing its 4f electrons to jump to the excited state, and then the upconverting emissions are obtained when electrons return to the ground state. Since the Tb-UCMOF nanosheets have high dispersibility and an obvious upconverting luminescent signal, we explored their luminescence sensing properties. The luminescence intensity is found to gradually decrease with the addition of Cu2+, the linear range of Cu2+ sensing is 0-1.4 μM, and the detection limit is 0.16 μM. This rapid, highly selective, and sensitive Cu2+ sensing indicates that 2-D upconverting MOF nanosheets have great application prospects in luminescence sensing and also promote the research of 2-D upconverting MOFs with specific recognition for the application of biological and environmental luminescent sensors.

Synthesis of the wire-in-tube structure porous C12H12O12S3Tb2@g-C3N4/ZnO luminescent composite in hydrothermal condition

The wire-in-tube structure was often prepared by electrostatic spinning method, and a kind of novel wire-in-tube structure porous C12H12O12S3Tb2 @g-C3N4/ZnO luminescent material was obtained by hydrothermal method in this study in which a wire-like C12H12O12S3Tb2 was wrapped in the inner layer of the porous tube-like g-C3N4/ZnO shell layer, and an obvious g-C3N4 narrow edge layer was distributed on the outer layer of the tube-like structure. Due to the wire-in-tube structure and the stronger UV absorption capacity of g-C3N4/ZnO matrix and organic ligand (SSA), the characteristic emission of Tb was greatly enhanced in the C12H12O12S3Tb2 @g-C3N4/ZnO phosphors which showed a very strong green light emission at 543 nm. On the other hand, the g-C3N4 shows much better absorbing ability to visible light which has been rarely used to optimize the luminescence properties of rare earth materials. In this study, the g-C3N4 showed the absorption to 490 nm emission light which was precisely used to improve the emission at 543 nm.

Preparation and luminescence properties of Tb3+ doped and Tb3+/Sm3+ co-doped Na3Y(PO4)2 crystalline glass ceramics

Tb4O7 doped and Sm2O3-Tb4O7 co-doped containing Na3Y(PO4)2 crystalline glass ceramics were prepared by melting crystallization,which heat treatment condition was 660 ℃/120 min. In the emission spectrum, there are characteristic peaks of Tb3+ at 416 nm, 437 nm, 489 nm, 545 nm, 585 nm, and 621 nm. In addition, the emission intensity at 545 nm is the strongest corresponding to the 5D4→7F5 transition of Tb3+. And the optimal doping concentration of Tb4O7 doped glass ceramics is 0.5%. Sm2O3-Tb4O7 co-doped glass ceramics were excited at 378 nm, and the characteristic emission of Tb3+ and Sm3+ could be obtained in the same spectrum. The energy transfer of Tb3+ to Sm3+ was proved by fluorescence lifetime and Dexter theory. Sm2O3-Tb4O7 co-doped Na3Y(PO4)2 crystal phase glass ceramics can be used in green lasers and White light-emitting diode (w-LEDs) by adjusting the doping concentration of Sm2O3 and Tb4O7.

Rare-Earth Doping Graphitic Carbon Nitride Endows Distinctive Multiple Emissions with Large Stokes Shifts

Rare-Earth Doping Graphitic Carbon Nitride Endows Distinctive Multiple Emissions with Large Stokes Shifts

Multi-color luminescence and energy transfer behavior of Ba3Lu4O9:Tb3+,Eu3+ phosphor for solid-state lighting

A multi-color-emitting phosphor Ba3Lu4O9:Tb3+,Eu3+ was synthesized by the high-temperature solid-state reaction. Under UV excitation, the characteristic emissions of Tb3+ and Eu3+ in Ba3Lu4O9 were observed simultaneously. The energy transfer behavior from Tb3+ to Eu3+ was verified and investigated through the photoluminescent spectra and the decay curves. The energy transfer efficiency was estimated to be 94.6% when the concentration of Eu3+ was 10 mol%, and the energy transfer process was determined by the dipole–dipole mechanism. The critical distance for the energy transfer between Tb3+ and Eu3+ was around 16.52 Å. Furthermore, the activation energy of Tb3+ (5D4-7F5) and Eu3+ (5D0-7F2) in Ba3Lu4O9 were calculated to be 0.323 eV and 0.499 eV, respectively. With the increase of Eu3+ concentration, the emitting color of the phosphors can be regulated from green (0.2923, 0.5228) to reddish orange (0.6196, 0.3346) with their respective CCT of 6463 K to 8909 K. All these findings indicate that the phosphor can be utilized as the multi-color component for solid-state lighting.

Photoluminescence features of green-emitting sol-gel synthesized La2W3O12 doped with Tb3+ phosphor for PDP applications

The La2-xW3O12:xTb (0.005 ≤ x ≤ 0.10) phosphors were synthesized by a sol-gel process. The structural characterization was carried out using powder X-ray diffraction (PXRD) and Fourier transform infrared spectra (FTIR) techniques. The crystallite size was estimated by Scherrer formula and it is found to be in the range of 45−56 nm. The excitation spectra for all the prepared phosphors were recorded under monitoring at 544 nm. The emission spectra recorded for different excitation wavelengths (274, 147 and 172 nm) show all the characteristic emissions of Tb3+ ions. Thus, the prepared phosphors are suitable for application in plasma display panels.

Luminescence sites and spectra of metal doped microwave synthesized Mg2SiO4:Tb

Terbium doped magnesium orthosilicate (Mg2SiO4: Tb) has been reported as the most efficient thermoluminescence dosimeter material. Further sensitivity improvements of Mg2SiO4: Tb may be achieved by co-doping with other metal ions. Performance is strongly influenced by the sintering conditions, as shown here for Mg2SiO4: Tb samples which were synthesized with microwave thermal processing. A series of Mg2SiO4: x mol% Tb (x = 0.5, 1, 3, 5, 7) and Mg2SiO4: Tb, M (M = Li, Na, Ca, Al, Ga) samples are compared. Photoluminescence (PL) and Thermoluminescence (TL) of all samples are dominated by the characteristic emission of Tb3+. Co-doping can improve the sensitivity, and this is linked to modification of the micro-structure, as revealed by SEM measurements. Among the co-doped samples investigated, Mg2SiO4: Tb, Na shows the highest TL response with the main TL peak at 196oC. Differences between processing with microwave heating and thermal sintering are apparent in terms of the association of the dopants. Benefits and future possibilities with wider applications are discussed.

Bifunctional sulfur-ligated erbium complex: Crystal structure, magnetic and luminescent properties

Two isostructural mononuclear rare-earth complexes, [(dbm)2Er(dtc)(phen)] (1-Er) and [(dbm)2Tb(dtc)(phen)] (2-Tb) (dbm− = dibenzoylmethanoate anion, dtc− = diethyldithiocarbamate anion, phen = 1, 10-phenanthroline) were synthesized and structurally characterized by single-crystal X-ray diffraction analyses. Each complex consists of one sulfur-donor ligand, two oxygen-donor ligands and one auxiliary ligand, and Er3+/Tb3+ ion locates in a distorted square antiprism. Magnetic measurements show that 1-Er displays slow magnetic relaxation behavior under an applied field, and solid-state emission spectra reveal that 1-Er exhibits characteristic emissions of Er3+ ion in the visible and near-infrared regions, indicating the dual functionality of 1-Er. Neither slow relaxation of the magnetization nor characteristic emissions of Tb3+ ion were observed for 2-Tb.

Luminescence and energy transfer of a novel tunable-emitting phosphor Sr0.8Ca0.2Al2Si2O8:Eu/Tb for white LEDs

A series of Sr0.8Ca0.2Al2Si2O8:Eu/Tb are synthesized, and the luminescence property and energy transfer of Eu2+, Tb3+, Eu3+ are explored. The results indicate that Sr0.8Ca0.2Al2Si2O8:Tb3+ presents the typical green emission, however, Eu2+ and Eu3+ coexist when Sr0.8Ca0.2Al2Si2O8:Eu is synthesized under air atmosphere. There is no the characteristic emission of Tb3+ in the emission spectra of Sr0.8Ca0.2Al2Si2O8:Eu, Tb synthesized in the atmosphere, but the emission spectra of Tb3+ appeared in the emission spectra of Sr0.8Ca0.2Al2Si2O8:Eu, Tb synthesized in the reducing condition. It may be deuced by the two forms of energy transfer: Eu2+→Tb3+ and Tb3+→Eu3+. And the energy transfer efficiency of Tb3+→Eu3+ is much greater than that of Eu2+→Tb3+. When Eu2+, Tb3+ and Eu3+ exist at the same time, there is the energy transfer of Eu2+→Tb3+→Eu3+. This result is of great significance for changing the luminescent properties of phosphors based on energy transfer.

Ratiometric fluorescence sensing of Fe2+/3+ by carbon dots doped lanthanide coordination polymers

In this work, we proposed a ratiomatric fluorescent strategy for sensing Fe2+ by using the carbon dots (CDs) doped lanthanide coordination polymers (Ln-CPs). Herein, the Ln-CPs were prepared by self-assemble of adenosine monophosphate (AMP) with Tb3+ (AMP-Tb) through coordination reaction, and CDs were encapsulated during the assembly process as guest materials. A cofactor, phenanthroline (Phen), could incorporate into the CDs@AMP-Tb, and strongly sensitized the luminescence of Tb3+ through energy transfer. Therefore, the obtained CDs@AMP/Phen-Tb could emit dual fluorescence signals. One is the characteristic emission of Tb3+, which could be specifically quenched by Fe2+ due to the high affinity between Phen and Fe2+. Another is originated from CDs encapsulated in Ln-CPs, which did not change in the presence of Fe2+. Subsequently, CDs@AMP/Phen-Tb was chosen as the ratiomatric fluorescent probe for sensing Fe2+, where the fluorescence of Tb3+ was quenched serving as the reporter, while that of CDs remained constant serving as the internal control for self-calibration. In addition, with the help of a reducing agent, which can reduce Fe3+ to Fe2+ efficiently, the proposed method can also be applied in selective detection Fe3+. By taking advantage of the unique property of Ln-CPs, the proposed strategy promises flexibility for designing of a series of ratiometric fluorescent sensors and expanded in practical applications.

Prominent blue emission through Tb3+ doped La2O3 nano-phosphors for white LEDs

In this article, we report the tunable luminescence emission of Tb3+ doped La2O3 nanophosphors synthesized by a facile and effective Polyol method. The structural and surface morphological studies have been carried out by employing X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD studies elucidate the proper phase formation and the results emanate from Raman spectroscopy of the as synthesized nanophosphor affirms it. The optical properties of the as fabricated nanoparticles have been investigated by Raman and photoluminescence (PL) spectroscopy. The PL spectroscopy shows the occurrence of excitation peaks at 305, 350 and 375 nm for 543 nm emissions, correspond to transition 5D4 →7F5. Emission spectra with 305 nm excitation exhibits characteristic emission peaks of Tb3+ion at 472, 487, 543 and 580 nm. The intensity of emission increases with Tb3+ concentration and is most prominent for 7 at% Tb3+ ion. The characteristic emissions of Tb3+ ion owes to the transition in which intensities of blue and green emission are prominent. The dominant intensity has been found for 472 nm (for blue emission). Commission international d 'Eclairage (CIE) co-ordinates have found in the light blue to green region. The research work provides a new interesting insight dealing with tunable properties with Tb3+ doping in La2O3 nanophosphors, to be useful for display devices, solar cells, LEDs and optoelectronic devices.

Synthesis, luminescent properties and energy transfer in Tb3+ and Eu3+ co-doped Li3Ba2Gd3 (MoO4)8 phosphors for W-LED’s

For the first time, single phase monoclinic Li3Ba2Gd3 (MoO4)8: 0.08 Tb3+,yEu3+ (0, 0.005, 0.02, 0.04, 0.06, 0.08 and 0.10 mol) nano phosphors were prepared by the simple mechanochemically assisted direct solid state reaction method at room temperature. Their crystal structures, luminescence properties, energy transfer mechanism and life time were studied in detail. At the excitation wavelength of 378 nm, the emission spectra of Li3Ba2Gd3 (MoO4)8: 0.08 Tb3+,yEu3+ (0, 0.005, 0.02, 0.04, 0.06, 0.08 and 0.10 mol) phosphors exhibit the characteristic emissions of Tb3+ and Eu3+ ions at around 545, 594 and 615 nm due to energy transfer from Tb3+ ions to Eu3+ ions. It is confirmed from the results that electric dipole–dipole interaction phenomena is the main cause for having energy transfer from Tb3+ to Eu3+ ions in Li3Ba2Gd3 (MoO4)8 host. The CIE coordinates of the prepared nano phosphors illustrate that by changing the ratio of Eu3+ ions the white light emission can be realized from Li3Ba2Gd3 (MoO4)8 phosphor and it coexist very close to an ideal white chromaticity coordinates (0.33, 0.33). All properties show that Li3Ba2Gd3 (MoO4)8: 0.08 Tb3+, 0.005 Eu3+ nano phosphor is a promising material for single-phase phosphor based white light emitting diodes.

Synthesis and photoluminescence properties of red, green and blue emitting LaYO3:M (M = Eu3+, Tb3+, Sm3+,Bi3+, Pb2+) phosphors

Red, green and blue light emitting Eu3+, Sm3+, Tb3+, Bi3+ and Pb2+ ions doped LaYO3 phosphors were synthesized by co-precipitation method and their photoluminescence (PL) properties were studied. The Eu3+-doped LaYO3 compound exhibited characteristic emissions of Eu3+. The intensity of PL emission peak found to be more at 614nm than 595nm. LaYO3:Sm3+ phosphor showed PL emission at 570nm, 608nm and 660nm which is characteristic emission of Sm3+. Tb3+ doped LaYO3 compound show intense emission at 545nm which again characteristic emission of Tb3+ in LaYO3 host. Eu3+, Tb3+ and Sm3+ doped LaYO3 phosphors displayed charge transfer band in UV region which is responsible for intense emission in red, orange and green region. Transition metal ions such as Pb2+ and Bi3+ doped LaYO3 phosphor exhibited PL emission in blue region. Prepared phosphors are useful to be used in display devices and related applications.

High-temperature long persistent and photo-stimulated luminescence in Tb3+ doped gallate phosphor

The formation of suitable defects levels is crucial to the optical performance of the electron trapping materials which provide a wide range of applications from the initial civil uses to life sciences, energy and environmental engineering. SrGa2O4, possessing a one-dimensional chain structure of cations along a crystal direction, exhibits a self-activated blue long persistent luminescence (LPL) related to the intrinsic defects. Different trap depths are generated forming a successive defect structure in this three-dimensional framework of SrGa2O4 containing channels occupied by Sr2+ when Tb3+ ions are introduced. The captured carriers in shallow traps are spontaneously released at room temperature and recombine in the luminescence center of Tb3+, eventually causing characteristic emission of Tb3+. The deeper traps are critically important to prevent the thermal fading of carriers at room temperature, therefore, LPL is achieved in SrGa2O4:Tb3+ phosphor at 328 K. Furthermore, a photo-stimulated luminescence (PSL) originated from Tb3+ ions is realized in SrGa2O4:Tb3+ phosphor induced by 980 nm laser diode with the releasing of the carriers trapped in the deeper traps at room temperature. Our results infer that the existence of a successive defect structure with multiple traps for the incorporation of the shallow and deep ones is conducive to the thermal stability of SrGa2O4:Tb3+ phosphor, which could provide a potential application in a rigorous environment with a higher thermal energy than the room temperature, such as solar energy utilization, and in vivo-imaging.

Synthesis and optical properties of Tb-doped pentazinc dimolybdate pentahydrate

Tb3+ doped pentazinc bimolybdate pentahydrate (Zn5Mo2O11·5H2O) was synthesized via the precipitation method. Thermal gravimetric analysis and differential scanning calorimetric analysis indicate that Zn5Mo2O11·5H2O is decomposed into ZnMoO4 at the phase transition temperature 267 °C. The photoluminescence characterization shows that the characteristic emissions of Tb3+ at 488, 544, 586 and 613 nm are superimposed over a broad emission band of Zn5Mo2O11·5H2O. The characteristic emissions of Tb3+ ions get weakened in intensity as the calcination temperature increases from 150 to 267 °C. Our results have demonstrated that Tb3+ can be used as an effective and direct probe in the spectroscopic studies on the phase transition of Zn5Mo2O11·5H2O.

Efficient resonance energy transfer study from Ce3+ to Tb3+ in BaMgF4

A low temperature precipitation method was employed for the synthesis of green emitting orthorhombic BaMgF4:Ce3+,Tb3+ phosphors. We investigated the structural, photoluminescence (PL) and energy transfer properties of the BaMgF4:Ce3+,Tb3+ phosphor. The PL emission spectrum of BaMgF4:Ce3+ shows two unresolved peaks at 315 nm and 336 nm, assigned to the lowest 5d level to the two J-multiplets of the 4f1 configuration of Ce3+. Characteristic emission of Tb3+ was observed at 546 nm which comes in the green region of the visible spectrum. The Ce co-doped BaMgF4:Tb3+ phosphor show strong PL emission in the green region, which is due to the resonance energy transfer from Ce3+ to Tb3+. Further, we have calculated the energy transfer parameters and discussed the energy transfer mechanism in detail. The thermal stability and quantum yield of the prepared phosphor was also studied. The obtained results reveal that BaMgF4:Ce3+,Tb3+ phosphor can be considered as a potential green emitting phosphor for optoelectronic applications.

Structure, luminescent and thermal properties of two novel lanthanide complexes with 3,4-diethoxybenzoic acid and 5,5′-dimethy-2,2′-bipyridine

Two new lanthanide complexes [Tb(3,4,-DEOBA)3 5,5′-DME-2,2′-BIPY]2 (1), [Dy(3,4,-DEOBA)35,5′-DME-2,2′-BIPY]2 (2)(3,4,-DEOBA=3,4-diethoxybenzoate,5,5′-DME-2,2′-BIPY=5,5′-dimethy-2,2′-bipyridine) have been synthesized and characterized by elemental analysis, IR spectra and powder X-ray diffraction. The single crystal of the complex 1 has been obtained. There are two kinds of coordination modes in complex, 1 and the Tb3+ ion is eight-coordinated. The luminescence spectra of complexes 1 and 2 show the characteristic emission of Tb3+ ion (5D4 → 7F6-3) and Dy3+ ion (4F9/2 → 6H15/2,6H13/2). The results of thermal decomposition mechanism of the title complexes show that two complexes are thermally stable. And the pathway of thermal decomposition has been investigated by the coupled TG-FTIR technique. In the thermal decomposition of the title complexes, neutral ligands lose firstly, and then 3,4-DEOBA decompose into gaseous molecules of H2O and CO2. The kinetics of the first decomposition stage for two complexes are investigated by using the integral isoconversional nonlinear (NL-INT) method, which suggests that the first decomposition step of two complexes is complex reactions. The heat capacities of title complexes were measured by DSC in the temperature range from 258.15 to 343.15 K. The smoothed heat capacities and thermodynamic functions of the complexes are calculated based on the fitted polynomial and thermodynamic equations. The antibacterial performance study of complexes shows that two complexes have good antibacterial activity against Candida albicans, Staphylococcus aureus and no bacteriostatic activity on Escherichia coli.

A new approach for synthesis of SiO2/poly(2-hydroxyethyl methacrylate):Tb3+ nanohybrids by combination of surface-initiated raft polymerization and coordination chemistry

A facile strategy for growing the poly(2-hydroxyethyl methacrylate) encapsulated on the surface of SiO2 nanoparticles (SiO2/PHEMA) as a molecular host matrix for the luminescent Tb3+ via a combination of surface-initiated reversible addition fragmentation chain transfer polymerization and coordination chemistry was successfully developed. The structure, morphology and fluorescence properties of the materials were investigated using relevant physical and spectral techniques. The core–shell structure and uniform dispersion of SiO2/PHEMA and SiO2/PHEMA:Tb3+ complexes were found according to SEM and TEM analyses while their surface bonding characteristics were determined via FT-IR analysis. In photoluminescence measurement, the SiO2/PHEMA:Tb3+ nanoparticles showed characteristic emissions of Tb3+ with the strongest (5D4 → 7F5) green emission without detectable emissions of ligands, demonstrating that SiO2 framework covalently bonded with PHEMA segments acting as an efficient matrix for sensitization of fluorescent Tb3+ ions.

A new one-pot strategy to LaF3:Ce,Tb@SiO2 core-shell nanostructures

Abstract LaF3:Ce,Tb@SiO2 core-shell nanostructures were synthesized using a new one-pot reverse microemulsion strategy. One-pot method facilitates the synthetic process of this kind of core-shell nanostructures. The crystalline phase, size, morphology, pore structure and luminescence properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), nitrogen physisorption isotherm, photoluminescence (PL) excitation and emission spectra. The results revealed that the core-shell nanostructures have an average diameter of about 27 nm and cores of about 3 nm, and that these nanostructures contain micropores with an average pore diameter of 0.43 nm. The characteristic emissions of Tb3+ were observed under the excitation of Ce3+ 4f–5d transition due to the energy transfer from Ce3+ to Tb3+. LaF3:Ce,Tb@SiO2 nanostructures can disperse well in water and the colloid can emit bright green light under ultraviolet (UV) irradiation.

SYNTHESIS AND FLUORESCENCE PROPERTIES OF LaF3:Tb3+ PHOSPHORS VIA ULTRASONIC-ASSISTED IONIC LIQUID METHOD

Hexagonal phase LaF 3: Tb 3+ nano/microcrystals were successfully synthesized via ultrasonic-assisted ionic liquid (IL) method. The field emission scanning electron microscope (FESEM) images revealed that the morphologies of the as-prepared LaF 3: Tb 3+ samples were gradually converted from nanoplates to microcylinders with increasing the concentration of Tb 3+ ions. The photoluminescent (PL) spectrum shows that all the as-prepared La 1-x Tb x F 3 samples show the characteristic emissions of Tb 3+5 D 4 → 7 F J (J = 6-3, with 5 D 4 → 7 F 5 green emission at 542 nm as the strongest one) transitions. The optimal Tb 3+-doped concentration is 20 mol.% in the LaF 3 host. The photoluminescence intensity of the La 0.80 Tb 0.20 F 3 microcylinders prepared by ultrasonic irradiation was largely improved as compared with that of the product prepared by stirring.