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Effects of Gd3+ codoping on the enhancement of the luminescent properties of a NaBi(MoO4)2:Eu3+ red-emitting phosphors
摘要： A series of NaBi(MoO4)2:Eu3+ and NaBi(MoO4)2:Eu3+, Gd3+ phosphors were prepared using a sol-combustion method. NaBi(MoO4)2:Eu3+ with a tetragonal scheelite structure was obtained by heat treatment at 600–800 °C. The effects of the synthetic temperature and Eu3+ concentration on the luminescent properties of the NaBi(MoO4)2:Eu3+ phosphors were investigated. Under blue excitation at 464 nm, the NaBi(MoO4)2:Eu3+ sample exhibited a strong red emission peak at 618 nm, which originated from the 5D0→7F2 transition of Eu3+. Furthermore, Gd3+ ions were codoped into NaBi(MoO4)2:Eu3+ to enhance the luminescent intensity of NaBi(MoO4)2:Eu3+, Gd3+ due to energy transfer between Gd3+ and Eu3+. The results indicated that the NaBi(MoO4)2:Eu3+, Gd3+ red phosphor could be applied to white light-emitting diodes to achieve excellent properties, such as a high color rendering index and low correlated color temperature.
关键词： NaBi(MoO4)2,Energy transfer,Luminescence enhancement,Codoping,Red phosphors
更新于2025-09-19 17:15:36
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Luminescence properties and energy transfer investigations of Ce3+ singly doped and Ce3+/Tb3+ codoped Na3LuSi2O7 phosphors
摘要： The Na3LuSi2O7:Ce3+ and Na3LuSi2O7:Ce3+, Tb3+ phosphors were synthesized under a weak reducing atmosphere by the traditional high temperature solid state reaction method. The synthesized phosphors were characterized by X-ray diffraction (XRD), Photoluminescence (PL) emission and excitation spectra. The effects of Ce3+ singly doped and Ce3+/Tb3+ codoped concentrations on the structure, luminescence properties and energy transfer of Na3LuSi2O7 phosphors were studied in detail. The results indicated that the energy transfers between Ce3+ and Tb3+ in the host occurred mainly via a dipole-quadrupole mechanism, and the critical distances of the ion pairs (Rc) were calculated by the quenching concentration method and spectral overlap method. Based on the good PL properties adjusting the doping concentration of the activators (Ce3+,Tb3+) might be promising as a host material for solid-state lighting and display fields.
关键词： Luminescence,Na3LuSi2O7:Ce3+,Tb3+ phosphors,Energy transfer
更新于2025-09-19 17:15:36
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Energy Transfer and Spectroscopic Investigation of Dy2O3 Doped Li2O–BaO–GdF3–SiO2 for White Light LED
摘要： LGFDy glasses doped with Dy2O3 (0.1, 0.5, 1.0, 1.5 and 2.0 mol %) were synthesised by conventional melt quenching method and various properties are studied by absorption, Judd–Ofelt analysis, photoluminescence, X-ray excited luminescence, decay curve and CIE color chromaticity measurement. Judd-Ofelt parameters (?2, ?4 and ?6) are valuated form JO theory in order to estimate the radiative parameters of the Dy3+ ion excited states. For white light emission, Yellow/Blue (Y/B) ratio and CIE color coordinates for glasses under study are measured from the emission spectra. The energy transfer from Gd3+ to Dy3+ ions has been studied by exciting the glass with 275 nm photon. The higher value of σ (λp) and βR for 4F9/2 → 6H13/2 transition indicates its more potential use in laser application in yellow region. The correlated color temperature for LGFDy glasses is found to be 4264 K. The decay profile of fluorescent level 4F9/2 for different concentration of Dy3+ ions in the present glasses changes to non-exponential from single-exponential for higher concentration (≥0.5 mol %) of Dy3+ ions. Thus the chemical composition of glass and dopant (Dy3+ ions) concentration strongly influence the energy transfer mechanism. The lifetime non-exponential behavior is well fitted to IH-model for S = 6. The quantum efficiency for LBGFDy05 glass is found to be 86%. The systematic investigation signifies the potential of the studied LGFDy glasses for the laser and white light generation application.
关键词： silicate glasses,dysprosium,decay time,energy transfer,resonance energy transfer
更新于2025-09-19 17:13:59
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Improvement of Exciton Collection and Light-Harvesting Range in Ternary Blend Polymer Solar Cells Based on Two Non-Fullerene Acceptors
摘要： A non‐fullerene molecule named Y6 was incorporated into a binary blend of PBDB‐T and IT‐M to further enhance photon harvesting in the near‐infrared (near‐IR) region. Compared with PBDB‐T/IT‐M binary blend devices, PBDB‐T/IT‐M/Y6 ternary blend devices exhibited an improved short‐circuit current density (JSC) from 15.34 to 19.09 mA cm?2. As a result, the power conversion efficiency (PCE) increased from 10.65% to 12.50%. With an increasing weight ratio of Y6, the external quantum efficiency (EQE) was enhanced at around 825 nm, which is ascribed to the absorption of Y6. At the same time, EQE was also enhanced at around 600–700 nm, which is ascribed to the absorption of IT‐M, although the optical absorption intensity of IT‐M decreased with increasing weight ratio of Y6. This is because of the efficient energy transfer from IT‐M to Y6, which can collect the IT‐M exciton lost in the PBDB‐T/IT‐M binary blend. Interestingly, the EQE spectra of PBDB‐T/IT‐M/Y6 ternary blend devices were not only increased but also red‐shifted in the near‐IR region with increasing weight ratio of Y6. This finding suggests that the absorption spectrum of Y6 is dependent on the weight ratio of Y6, which is probably due to different aggregation states depending on the weight ratio. This aggregate property of Y6 was also studied in terms of surface energy.
关键词： non‐fullerene,exciton harvesting,surface energy,ternary blend solar cells,energy transfer
更新于2025-09-19 17:13:59
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Enhancing the organic solar cell efficiency by combining plasmonic and F?rster Resonance Energy Transfer (FRET) effects
摘要： Here, we combine two strategies i.e., F€orster resonance energy transfer and plasmonic effect, to enhance the photovoltaic performance in organic solar cells by introducing gold nanoparticles and squaraine in a binary mixture of poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester. In this configuration, the F€orster resonance energy transfer between poly(3-hexylthiophene) and squaraine reduces the electrical loss arising from the exciton recombination in poly(3-hexylthiophene), while gold nanoparticles enable an efficient charge carrier generation in poly(3-hexylthiophene):squaraine mixture as optically confirmed by photoluminescence measurement and transient absorption spectroscopy. The multicomponent organic solar cells demonstrate an enhancement of ~36% in power conversion efficiency over the reference device.
关键词： Organic solar cells,Plasmonic effect,Squaraine,Gold nanoparticles,F€orster resonance energy transfer
更新于2025-09-19 17:13:59
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Self-Assembled Nanohelix for White Circularly Polarized Luminescence via Chirality and Energy Transfer
摘要： Chiral nanostructures and their optical activity have been attracting great interest. Here, we designed enantiomer bolaamphiphile containing a naphthalene moiety (bola-1) and alkyl spacer, and investigated their self-assembly as well as optical activity. It was found the compound could form gels in various organic or mixed organic/water mixtures. In mixed DMSO/water, it formed nanohelix. Due to the fluorescent nature of the naphthyl group, the nanohelix showed both CD and circularly polarized luminescence (CPL). When three achiral fluorescent molecules, pyrene-1-carboxylic acid (D2), rhodamine 110 (D3) and rhodamine B (D4), were incorporated into the helical structures formed by bola-1, the nanohelix could be remained and the CPL from the dye molecules could be induced. In addition, an energy transfer occurred between the bola-1 nanohelix and the dyes. By mixing the different emission dyes with the bola-1 in an appropriated ratio, a white CPL was obtained. It was found the dissymmetry factor of the white CPL could be increased through the energy transfer. This work provided a new convenient and efficient way of fabricating while CPL.
关键词： nanohelix,white CPL,circularly polarized luminescence,energy transfer,optical activity,Chiral nanostructures,bolaamphiphile
更新于2025-09-19 17:13:59
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Interaction features of two ultra-intense laser pulses self-trapped in underdense plasmas
摘要： The interaction of two parallel relativistic laser beams in underdense plasmas is investigated by considering the evolution of their wave envelopes. The energy transfer between the two lasers is given by an expression based on the evolution of the total laser power in a regime without beam mixing. It is shown that how the energy is transferred depends nonlinearly on the initial phase difference of the lasers, and the result of the interaction depends on the laser intensity, spot radius, and their separation distance. The results are verified by direct numerical solution of the relativistic nonlinear Schr?dinger equations for the laser envelopes as well as particle-in-cell simulation. The study and results should be helpful for understanding the energy transfer behavior of multiple co-propagating laser beams in underdense plasmas.
关键词： nonlinear Schr?dinger equations,underdense plasmas,energy transfer,laser beams,particle-in-cell simulation
更新于2025-09-19 17:13:59
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Mechanistic Insight into Energy Transfer Dynamics and Color Tunability of Na4CaSi3O9:Tb3+, Eu3+ for Warm White LEDs
摘要： We propose a latent energy transfer process in traditional Eu3+, Tb3+-doped phosphors and present a new class of Eu3+, Tb3+-doped Na4CaSi3O9 phosphors, enabled by luminescence decay dynamics that optimize the electron-transfer energy process. Compared with other Eu3+, Tb3+-doped phosphors, the as-synthesized Eu3+, Tb3+-doped Na4CaSi3O9 phosphors show improved large-scale tunable emission color from green to red upon UV excitation, controlled by the Tb3+/Eu3+ doping ratio. Detailed spectroscopic measurements in the VUV-UV-vis region were used to determine the Eu3+-O2- charge transfer energy, 4f-5d transition energies and the energies of 4f excited multiplets of Eu3+ and Tb3+ with different 4fN electronic configurations. The Tb3+→Eu3+ energy transfer pathway in the co-doped sample was systematically investigated, employing luminescence decay dynamics analysis to elucidate the relevant energy transfer mechanism in combination with the appropriate model simulation. To demonstrate their application potential, a prototype white light-emitting diode (WLED) device was successfully fabricated using the yellow luminescence NCSO:0.03Tb3+,0.05Eu3+ phosphor with high thermal stability and a BaMgAl10O17:Eu2+ phosphor in combination with a near-UV chip. These findings open up a new avenue to realize and develop multifunctional high-performance phosphors by manipulating the energy transfer process for practical applications.
关键词： Luminescence,Energy transfer,Phosphor,Luminescence decay dynamics,Rare earth
更新于2025-09-19 17:13:59
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Energy transfer and thermal stability of novel green-emitting Ca3Y(PO4)3:Ce3+, Tb3+ phosphors for white LEDs
摘要： A novel thermally high-stable and high-e?ciency green-emitting Ce3+/Tb3+ co-doped Ca3Y(PO4)3 phosphor has been successfully synthesized via a conventional solid-state reaction. The energy transfer and thermal quenching of Ca3Y(PO4)3:Ce3+, Tb3+ samples were investigated for the ?rst time. The emission spectra of as-prepared samples presented a blue emission band deriving from the 5d-4f transition of Ce3+ and green emission peaks stemmed from 5D4-7FJ (J = 6, 5, 4, 3) of Tb3+ upon 325 nm excitation. By adjusting Tb3+ concentration, the chromaticity coordinates of as-prepared samples could be tuned from (0.165, 0.028) to (0.301, 0.529) because of the energy transfer of Ce3+→Tb3+ ions. It was demonstrated that the energy transfer mechanism from Ce3+ to Tb3+ ions in Ca3Y(PO4)3 host is the electric dipole-dipole interaction by the energy level diagram and the spectral overlap between the emission spectrum of the donor and the excitation spectrum of the acceptor. The energy transfer e?ciency from Ce3+ to Tb3+ ions in Ca3Y(PO4)3 was up to 81%. Beyond that, it a?rmed that the emission intensity at 423 K was about 82% of that measured at room temperature (298 K) according to the temperature-dependent emission spectra. Basing on the above analyses shows that the as-synthesized green-emitting Ce3+/Tb3+ co-doped Ca3Y(PO4)3 phosphors with high energy transfer e?ciency and excellent thermal stability could be used in phosphor-converted white light-emitting-diodes (LEDs).
关键词： Thermal stability,Luminescence,Phosphor,Ca3Y(PO4)3,Energy transfer
更新于2025-09-19 17:13:59
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Development of a Prea??assembled TBET Fluorescent Probe for Ratiometric Sensing of Anticancer Platinum(ll) Complexes
摘要： Fluorescence microscopy has emerged as an attractive technique to probe intracellular processing of Pt-based anticancer compounds. Herein, we reported the first Through-Bond Energy Transfer (TBET) fluorescent probe NPR1 designed for sensitive detection and quantitation of PtII complexes. The novel TBET probe was successfully applied for ratiometric fluorescence imaging of anticancer PtII complexes such as cisplatin and JM118 in cells. Capitalizing on the ability of the probe to discriminate between PtII complexes and their PtIV derivatives, the probe was further applied to study the activation of PtIV prodrug complexes that are known to release active PtII species after intracellular reduction.
关键词： Platinum Drugs,Fluorescent Probes,Ratiometric,Cisplatin,Through Bond Energy Transfer
更新于2025-09-19 17:13:59