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Beatriz C Barja - One of the best experts on this subject based on the ideXlab platform.
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a six armed phenhomazine ligand with a potential turn off copper ii sensing capability through terbium iii Luminescence Quenching
Chemistry: A European Journal, 2020Co-Authors: Leandro Trupp, Andrea C Bruttomesso, Svetlana V Eliseeva, Stephane Petoud, Javier A Ramirez, Beatriz C BarjaAbstract:Herein, the design, synthesis, and characterization of a phenhomazine ligand are described. The ligand has six pendant acetate arms designed for the combined coordination of copper(II) and lanthanide(III) ions, with the perspective of developing a "turn-off" copper sensor. The key step for the ligand preparation was the one-step endomethylene bridge fission of a diamino Troger's base with a concomitant alkylation. Fluorescence and absorption spectroscopies as well as nuclear magnetic resonance (NMR) experiments were performed to analyze and understand the coordination properties of the ligand. Transition metal coordination was driven by the synergistic effect of the free nitrogen atoms of the diazocinic core and the two central acetate arms attached to those nitrogen atoms, whereas lanthanide coordination is performed by the external acetate arms, presumably forming a self-assembled 2:2 metallosupramolecular structure. The terbium complex shows the typical green emission with narrow bands and long Luminescence lifetimes. The Luminescence Quenching produced by the presence of copper(II) ions was analyzed. This work sets, therefore, a starting point for the development of a phenhomazine-based "turn-off" copper(II) sensor.
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a six armed phenhomazine ligand with a potential turn off copper ii sensing capability through terbium iii Luminescence Quenching
Chemistry: A European Journal, 2020Co-Authors: Leandro Trupp, Andrea C Bruttomesso, Svetlana V Eliseeva, Stephane Petoud, Javier A Ramirez, Beatriz C BarjaAbstract:Herein we describe the design, synthesis and characterization of a phenhomazine ligand with six pendant acetate arms designed for the combined coordination of copper(II) and lanthanide(III) ions, with the perspective of the development of a "turn-off" copper sensor. The key step for the ligand preparation was the one-step endomethylene bridge fission of a diamino Troger's base with a concomitant alkylation. Fluorescence and absorption spectroscopies as well as nuclear magnetic resonance (NMR) experiments were performed in order to analyze and understand the coordination properties of the ligand. Transition metal coordination was driven by the synergistic effect of the free nitrogen atoms of the diazocinic core and the two central acetate arms attached to those nitrogens, whereas lanthanide coordination is performed by external acetate arms, presumably forming a self-assembled 2:2 metallosupramolecular structure. The terbium complex shows the typical green emission with narrow bands and long Luminescence lifetimes. The Luminescence Quenching produced by the presence of copper(II) ions was analyzed. This work sets therefore a starting point for the development of a phenhomazine-based "turn-off" copper(II) sensor.
Cees Ronda - One of the best experts on this subject based on the ideXlab platform.
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Luminescence and Luminescence Quenching in gd3 ga al 5o12 scintillators doped with ce3
Journal of Physical Chemistry A, 2013Co-Authors: J M Ogieglo, Andries Meijerink, Cees Ronda, Arturas Katelnikovas, Aleksander Zych, Thomas JustelAbstract:The optical properties of gadolinium gallium aluminum garnet, Gd3(Ga,Al)5O12, doped with Ce(3+) are investigated as a function of the Ga/Al ratio, aimed at an improved understanding of the energy flow and Luminescence Quenching in these materials. A decrease of both the crystal field strength and band gap with increasing content of Ga(3+) is observed and explained by the geometrical influence of Ga(3+) on the crystal field splitting of the 5d level in line with theoretical work of Munoz-Garcia et al. ( unoz-Garcia, A. B.; Seijo, L. Phys. Rev. B 2010, 82, 184118 ). Thermal Quenching results in shorter decay times as well as reduced emission intensities for all samples in the temperature range from 100 to 500 K. An activation energy for emission Quenching is calculated from the data. The band gap of the host is measured upon Ga substitution and the decrease in band gap is related to Ga(3+) substitution into tetrahedral sites after all octahedral sites are occupied in the garnet material. Based on the change in band gap and crystal field splitting, band diagrams can be constructed explaining the low thermal Quenching temperatures in the samples with high Ga content. The highest Luminescence intensity is found for Gd3(Ga,Al)5O12 with 40% of Al(3+) replaced by Ga(3+).
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Luminescence and Luminescence Quenching in gd3 ga al 5o12 scintillators doped with ce3
Journal of Physical Chemistry A, 2013Co-Authors: J M Ogieglo, Andries Meijerink, Arturas Katelnikovas, Aleksander Zych, Thomas Justel, Cees RondaAbstract:The optical properties of gadolinium gallium aluminum garnet, Gd3(Ga,Al)5O12, doped with Ce3+ are investigated as a function of the Ga/Al ratio, aimed at an improved understanding of the energy flow and Luminescence Quenching in these materials. A decrease of both the crystal field strength and band gap with increasing content of Ga3+ is observed and explained by the geometrical influence of Ga3+ on the crystal field splitting of the 5d level in line with theoretical work of Munoz-Garcia et al. (Munoz-Garcia, A. B.; Seijo, L.Phys. Rev. B 2010, 82, 184118). Thermal Quenching results in shorter decay times as well as reduced emission intensities for all samples in the temperature range from 100 to 500 K. An activation energy for emission Quenching is calculated from the data. The band gap of the host is measured upon Ga substitution and the decrease in band gap is related to Ga3+ substitution into tetrahedral sites after all octahedral sites are occupied in the garnet material. Based on the change in band g...
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temperature Quenching of yellow ce3 Luminescence in yag ce
Chemistry of Materials, 2009Co-Authors: Volker Bachmann, Cees Ronda, Andries MeijerinkAbstract:Yttrium aluminum garnet (YAG) doped with Ce3+ is the phosphor of choice for the conversion of blue to yellow light in the rapidly expanding market of white light LEDs, but it is generally thought to suffer from a low Luminescence Quenching temperature. The Luminescence Quenching temperature is an important parameter, especially in high-power LEDs, but surprisingly no systematic research has been done to measure and understand the temperature Quenching of the yellow Ce Luminescence in YAG:Ce. Here we report on the Luminescence temperature Quenching in YAG:Ce. For a wide range of Ce concentrations (between 0.033% and 3.3%) the temperature dependence of the emission intensity and the Luminescence lifetimes are reported. The intrinsic Quenching temperature of the Ce Luminescence is shown to be very high (>700 K). The lower Quenching temperatures reported in the literature are explained by thermally activated concentration Quenching (for highly doped systems) and the temperature dependence of the oscillator st...
Andries Meijerink - One of the best experts on this subject based on the ideXlab platform.
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oxidation and Luminescence Quenching of europium in bamgal10o17 blue phosphors
Chemistry of Materials, 2017Co-Authors: Lucia Amidani, Andries Meijerink, Katleen Korthout, Jonas Joos, Marte Van Der Linden, Heleen Sijbom, Dirk Poelman, Philippe Smet, Pieter GlatzelAbstract:The efficient blue Luminescence of Eu2+ doped BaMgAl10O17 is well-known to be severely degraded by prolonged irradiation with vacuum-ultraviolet light. The degradation process at the atomic level is however not fully understood. In this work we employed X-rays as an equivalent but accelerated cause of degradation, as an excitation source of Luminescence and as an element-selective probe of both dopants and host-lattice chemical species. The X-ray absorption near edge structure (XANES) recorded in high energy resolution mode reveals that the structural properties of the host lattice are preserved during irradiation, while Eu2+ is rapidly oxidized. The correlation between Eu oxidation as derived from XANES and the decrease of blue Luminescence is however not linear and a significant fraction of Eu2+ survives degradation, implying additional mechanisms for the Quenching of the Luminescence. Defects created during the photogeneration may reduce the ability of the remaining Eu2+ to receive or to radiatively re...
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insight into the thermal Quenching mechanism for y3al5o12 ce3 through thermoLuminescence excitation spectroscopy
Journal of Physical Chemistry C, 2015Co-Authors: Jumpei Ueda, Andries Meijerink, P Dorenbos, Setsuhisa TanabeAbstract:Y3Al5O12(YAG):Ce3+ is the most widely applied phosphor in white LEDs (w-LEDs) because of strong blue absorption and efficient yellow Luminescence combined with a high stability and thermal Quenching temperature, required for the extreme operating conditions in high-power w-LEDs. The high Luminescence Quenching temperature (∼600 K) has been well established, but surprisingly, the mechanism for temperature Quenching has not been elucidated yet. In this report we investigate the possibility of thermal ionization as a cause of this Quenching process by measuring thermoLuminescence (TL) excitation spectra at various temperatures. In the TL excitation (TLE) spectrum at room temperature there is no Ce3+:5d1 band (the lowest excited 5d level). However, in the TLE spectrum at 573 K, which corresponds to the onset temperature of Luminescence Quenching, a TLE band due to the Ce3+:5d1 excitation was observed at around 450 nm. On the basis of our observations we conclude that the Luminescence Quenching of YAG:Ce3+ at ...
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Luminescence and Luminescence Quenching in gd3 ga al 5o12 scintillators doped with ce3
Journal of Physical Chemistry A, 2013Co-Authors: J M Ogieglo, Andries Meijerink, Arturas Katelnikovas, Aleksander Zych, Thomas Justel, Cees RondaAbstract:The optical properties of gadolinium gallium aluminum garnet, Gd3(Ga,Al)5O12, doped with Ce3+ are investigated as a function of the Ga/Al ratio, aimed at an improved understanding of the energy flow and Luminescence Quenching in these materials. A decrease of both the crystal field strength and band gap with increasing content of Ga3+ is observed and explained by the geometrical influence of Ga3+ on the crystal field splitting of the 5d level in line with theoretical work of Munoz-Garcia et al. (Munoz-Garcia, A. B.; Seijo, L.Phys. Rev. B 2010, 82, 184118). Thermal Quenching results in shorter decay times as well as reduced emission intensities for all samples in the temperature range from 100 to 500 K. An activation energy for emission Quenching is calculated from the data. The band gap of the host is measured upon Ga substitution and the decrease in band gap is related to Ga3+ substitution into tetrahedral sites after all octahedral sites are occupied in the garnet material. Based on the change in band g...
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Luminescence and Luminescence Quenching in gd3 ga al 5o12 scintillators doped with ce3
Journal of Physical Chemistry A, 2013Co-Authors: J M Ogieglo, Andries Meijerink, Cees Ronda, Arturas Katelnikovas, Aleksander Zych, Thomas JustelAbstract:The optical properties of gadolinium gallium aluminum garnet, Gd3(Ga,Al)5O12, doped with Ce(3+) are investigated as a function of the Ga/Al ratio, aimed at an improved understanding of the energy flow and Luminescence Quenching in these materials. A decrease of both the crystal field strength and band gap with increasing content of Ga(3+) is observed and explained by the geometrical influence of Ga(3+) on the crystal field splitting of the 5d level in line with theoretical work of Munoz-Garcia et al. ( unoz-Garcia, A. B.; Seijo, L. Phys. Rev. B 2010, 82, 184118 ). Thermal Quenching results in shorter decay times as well as reduced emission intensities for all samples in the temperature range from 100 to 500 K. An activation energy for emission Quenching is calculated from the data. The band gap of the host is measured upon Ga substitution and the decrease in band gap is related to Ga(3+) substitution into tetrahedral sites after all octahedral sites are occupied in the garnet material. Based on the change in band gap and crystal field splitting, band diagrams can be constructed explaining the low thermal Quenching temperatures in the samples with high Ga content. The highest Luminescence intensity is found for Gd3(Ga,Al)5O12 with 40% of Al(3+) replaced by Ga(3+).
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high temperature Luminescence Quenching of colloidal quantum dots
ACS Nano, 2012Co-Authors: Yiming Zhao, Charl F Riemersma, Francesca Pietra, Rolf Koole, Celso De Mello Donega, Andries MeijerinkAbstract:Thermal Quenching of quantum dot (QD) Luminescence is important for application in luminescent devices. Systematic studies of the Quenching behavior above 300 K are, however, lacking. Here, high-temperature (300–500 K) Luminescence studies are reported for highly efficient CdSe core–shell quantum dots (QDs), aimed at obtaining insight into temperature Quenching of QD emission. Through thermal cycling (yoyo) experiments for QDs in polymer matrices, reversible and irreversible Luminescence Quenching processes can be distinguished. For a variety of core–shell systems, reversible Quenching is observed in a similar temperature range, between 100 and 180 °C. The irreversible Quenching behavior varies between different systems. Mechanisms for thermal Quenching are discussed.
Ping Chen - One of the best experts on this subject based on the ideXlab platform.
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high performance and stable all inorganic perovskite light emitting diodes by reducing Luminescence Quenching at pedot pss perovskites interface
Organic Electronics, 2019Co-Authors: Yan Meng, Mahshid Ahmadi, Zuhong Xiong, Ping ChenAbstract:Abstract Compared to organic-inorganic halide perovskites (e.g., MAPbBr3 and FAPbBr3), all-inorganic CsPbBr3 perovskite has shown to be a more promising candidate for application in light-emitting diodes (LEDs) due to higher photoLuminescence quantum efficiency and thermal stability. Yet, the external quantum efficiency (EQE) of polycrystalline (3D) CsPbBr3 based PeLEDs needs further improvement. The low efficiency was attributed to severe Luminescence Quenching at PEDOT:PSS (Poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate))/CsPbBr3 interface arising from (i) interfacial energy barrier between PEDOT:PSS and CsPbBr3 layer, (ii) poor crystallization and large pinholes in perovskite film, and (iii) indium tin oxide (ITO) anode etching due to PEDOT:PSS acidity. Therefore, it is necessary to address all these problems simultaneously to reduce the Luminescence Quenching and to improve device efficiency. Here, we introduce a feasible approach to modify the PEDOT:PSS layer in order to reduce the Luminescence Quenching at PEDOT:PSS/CsPbBr3 interface. In this modification, PEDOT:PSS is mixed with a MoO3 ammonia solution at desired volume ratios. Our studies demonstrate that upon this treatment, not only hole injection and crystallization of perovskite film are improved but also ITO is protected from etching by the acidic nature of PEDOT:PSS. This modification result in a high performance all inorganic CsPbBr3 LED with a maximum luminance of ∼34420 cd/m2 and a current efficiency of ∼7.30 cd/A. In addition, our state-of-the-art perovskite LEDs (PeLEDs) exhibit no degradation after 2 h of continuous operation, representing a stable PeLEDs based on one-step solution processed polycrystalline CsPbBr3.
Javier A Ramirez - One of the best experts on this subject based on the ideXlab platform.
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a six armed phenhomazine ligand with a potential turn off copper ii sensing capability through terbium iii Luminescence Quenching
Chemistry: A European Journal, 2020Co-Authors: Leandro Trupp, Andrea C Bruttomesso, Svetlana V Eliseeva, Stephane Petoud, Javier A Ramirez, Beatriz C BarjaAbstract:Herein, the design, synthesis, and characterization of a phenhomazine ligand are described. The ligand has six pendant acetate arms designed for the combined coordination of copper(II) and lanthanide(III) ions, with the perspective of developing a "turn-off" copper sensor. The key step for the ligand preparation was the one-step endomethylene bridge fission of a diamino Troger's base with a concomitant alkylation. Fluorescence and absorption spectroscopies as well as nuclear magnetic resonance (NMR) experiments were performed to analyze and understand the coordination properties of the ligand. Transition metal coordination was driven by the synergistic effect of the free nitrogen atoms of the diazocinic core and the two central acetate arms attached to those nitrogen atoms, whereas lanthanide coordination is performed by the external acetate arms, presumably forming a self-assembled 2:2 metallosupramolecular structure. The terbium complex shows the typical green emission with narrow bands and long Luminescence lifetimes. The Luminescence Quenching produced by the presence of copper(II) ions was analyzed. This work sets, therefore, a starting point for the development of a phenhomazine-based "turn-off" copper(II) sensor.
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a six armed phenhomazine ligand with a potential turn off copper ii sensing capability through terbium iii Luminescence Quenching
Chemistry: A European Journal, 2020Co-Authors: Leandro Trupp, Andrea C Bruttomesso, Svetlana V Eliseeva, Stephane Petoud, Javier A Ramirez, Beatriz C BarjaAbstract:Herein we describe the design, synthesis and characterization of a phenhomazine ligand with six pendant acetate arms designed for the combined coordination of copper(II) and lanthanide(III) ions, with the perspective of the development of a "turn-off" copper sensor. The key step for the ligand preparation was the one-step endomethylene bridge fission of a diamino Troger's base with a concomitant alkylation. Fluorescence and absorption spectroscopies as well as nuclear magnetic resonance (NMR) experiments were performed in order to analyze and understand the coordination properties of the ligand. Transition metal coordination was driven by the synergistic effect of the free nitrogen atoms of the diazocinic core and the two central acetate arms attached to those nitrogens, whereas lanthanide coordination is performed by external acetate arms, presumably forming a self-assembled 2:2 metallosupramolecular structure. The terbium complex shows the typical green emission with narrow bands and long Luminescence lifetimes. The Luminescence Quenching produced by the presence of copper(II) ions was analyzed. This work sets therefore a starting point for the development of a phenhomazine-based "turn-off" copper(II) sensor.
