Cathodoluminescence properties of gadolinium-doped CaMoO4:Eu nanoparticles

Ramakrishna, P.

doi:10.1016/j.saa.2015.04.047

Cited by 13 publications

(2 citation statements)

References 18 publications

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“…In addition, this technique has the added advantage of operating at high excitation energy, allowing observation of optical transitions whose excitation is complicated or impossible to detect using conventional light sources . CL is also considered a powerful technique to study the location and identification of crystal defects in semiconductors. − It has also been used to investigate phosphorescent properties, − radiation detector materials, sedimentary rocks and petrographic marbles, , and nanophosphor-assisted biological cell imaging …”

Section: Introductionmentioning

confidence: 99%

Distribution of Eu²⁺ and Eu³⁺ Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study

Zavala‐Sanchez

Hirata

Novitskaya

et al. 2015

ACS Biomater. Sci. Eng.

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We present a cathodoluminescence study of the spatial distribution of Eu2+ and Eu3+ dopants in hydroxyapatite powders. The results demonstrate that the distribution of europium ions in the hydroxyapatite lattice depends on their valence state. Monochromatic cathodoluminescence images from prismatic powders show that although the Eu2+ is distributed homogeneously in the entire powder volume, the Eu3+ is present mainly at the powder edges. The luminescence spectrum of the Eu2+ ions displayed a wide and strong blue emission centered at 420 nm, while the luminescence spectrum of the Eu3+ ions displayed several orange-red emissions covering the range from 575 to 725 nm. These emissions correspond to transitions between levels 4f65d1-4f7 (8S7/2) of the Eu2+ ions and 5D0-7FJ levels of the Eu3+ ions. Micro Raman measurements reveal that europium doping generates two phonon signals with frequencies of 555 and 660 cm–1, both of which have not been reported earlier. The powders were synthesized by the combustion synthesis method, maintaining constant the concentration of the europium salt used, and varying the pH of the precursor solutions to modify the concentration ratio of Eu2+ with respect to Eu3+. X-ray photoelectron spectroscopy measurements were used to determine values of 0.32 and 0.55 for the ratio Eu2+/Eu3+ in samples synthesized at pH values of 6 and 4, respectively. Thermal treatments of the samples, at 873 K in an oxygen atmosphere, resulted in a strong quenching of the Eu2+ luminescence due to oxidation of the Eu2+ ions into Eu3+, as well as probable elimination of calcium vacancy defects by annealing.

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Section: Introductionmentioning

confidence: 99%

Distribution of Eu²⁺ and Eu³⁺ Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study

Zavala‐Sanchez

Hirata

Novitskaya

et al. 2015

ACS Biomater. Sci. Eng.

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“…Among the RE ions, special attention should be paid to trivalent gadolinium (Gd) ions since their excitations to highenergy states can result in efficient energy transfer from Gd 3+ to other lanthanide ions, allowing the achievement of emission 6 G J -6 P J in the visible range, thus gadolinium doping demonstrating enhanced emission. [17][18][19][20] It is worth mentioning that host materials consisting of d-block transition elements (e.g., molybdate) outperform other host lattices due to their broad excitation band stemming from the charge transport in the UV region between O and Mo. Therefore, gadolinium molybdate (Gd 2 (MoO 4 ) 3 , GMO) holds great promise in acting as host matrix.…”

Section: Introductionmentioning

confidence: 99%

Efficient charge transfer and utilization of near-infrared solar spectrum by ytterbium and thulium codoped gadolinium molybdate (Gd₂(MoO₄)₃:Yb/Tm) nanophosphor in hybrid solar cells

Sun

Chen

Qin

et al. 2016

Phys. Chem. Chem. Phys.

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In this work, thulium and ytterbium codoped gadolinium molybdate (Gd(MoO):Yb/Tm) nanophosphors (NPs) have been synthesized, followed by being incorporated into a photo-catalytic titania (TiO) nanoparticle layer. In detail, morphology and phase identification of the prepared NPs are first characterized and then the up-conversion of the Gd(MoO):Yb/Tm NPs is studied. Electron transfer dynamics after interfacing with bare or NP-doped electron donor TiO and the corresponding photovoltaic performance of solar cells are explored. The results show that Gd(MoO):Yb/Tm NPs excited at 976 nm exhibit intense blue (460-498 nm) and weak red (627-669 nm) emissions. The lifetime of electron transfer is shortened from 817 to 316 ps after incorporating NPs and correspondingly the electron transfer rate outstrips by 3 times that of the bare TiO. Consequently, a notable power conversion efficiency of 4.15% is achieved as compared to 3.17% of pure TiO/PTB7. This work demonstrates that the co-doping of robust rare earth ions with different unique functions can widen the harvesting range of the solar spectrum, boost electron transfer rate and eventually strengthen device performance, without complicated interfacial and structural engineering.

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Lanthanide-doped orthometallate phosphors

Ningombam

Singh

2020

Spectroscopy of Lanthanide Doped Oxide Materials

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Cathodoluminescence properties of gadolinium-doped CaMoO4:Eu nanoparticles

Cited by 13 publications

References 18 publications

Distribution of Eu²⁺ and Eu³⁺ Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study

Distribution of Eu²⁺ and Eu³⁺ Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study

Efficient charge transfer and utilization of near-infrared solar spectrum by ytterbium and thulium codoped gadolinium molybdate (Gd₂(MoO₄)₃:Yb/Tm) nanophosphor in hybrid solar cells

Lanthanide-doped orthometallate phosphors

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Cathodoluminescence properties of gadolinium-doped CaMoO4:Eu nanoparticles

Cited by 13 publications

References 18 publications

Distribution of Eu2+ and Eu3+ Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study

Distribution of Eu2+ and Eu3+ Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study

Efficient charge transfer and utilization of near-infrared solar spectrum by ytterbium and thulium codoped gadolinium molybdate (Gd2(MoO4)3:Yb/Tm) nanophosphor in hybrid solar cells

Lanthanide-doped orthometallate phosphors

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Distribution of Eu²⁺ and Eu³⁺ Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study

Distribution of Eu²⁺ and Eu³⁺ Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study

Efficient charge transfer and utilization of near-infrared solar spectrum by ytterbium and thulium codoped gadolinium molybdate (Gd₂(MoO₄)₃:Yb/Tm) nanophosphor in hybrid solar cells