scholarly journals Luminescent Properties of Eu3+-Doped Hybrid SiO2-PMMA Material for Photonic Applications

Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 441 ◽  
Author(s):  
Pablo Trejo-García ◽  
Rodolfo Palomino-Merino ◽  
Juan De la Cruz ◽  
José Espinosa ◽  
Raúl Aceves ◽  
...  

Hybrid organic-inorganic materials are of great interest for various applications. Here, we report on the synthesis and optical characterization of silica-PMMA samples with different Eu3+ molar concentrations. The optical properties of this material make it suitable for photonic applications. The samples were prepared using the sol-gel method, mixing tetraethyl orthosilicate (TEOS) as a silica glass precursor and methyl methacrylate (PMMA) as a polymer component. Europium nitrate pentahydrate was then added in six different molar concentrations (0.0, 0.1, 0.25, 0.5, 0.75, and 1%) to obtain as many different samples of the material. The absorption spectra were obtained applying the Kubelka–Munk formula to the diffuse reflectance spectra of the samples, all in the wavelength range between 240 and 2500 nm. The emission and excitation measurements were made in the visible range. Five bands could be identified in the emission spectra, related to electronic transitions of the ion Eu3+ (4D0→7Fi, i from 0 to 4). In the excitation spectra, the following bands were detected: 7F0→5G3 (379 nm), 7F0→5G2 (380 nm), 7F0→5L6 (392 nm), 7F0→5D3 (407 nm), 7F0→5D2 (462 nm), and 7F0→5D1 (530 nm). The emission decay times were measured for the different samples and showed an inverse dependence with the Eu3+ concentration.

2007 ◽  
Vol 336-338 ◽  
pp. 593-596
Author(s):  
Chun Yang ◽  
Jun Ying Zhang ◽  
Hai Bing Feng ◽  
Wei Chang Hao ◽  
Tian Min Wang

Y2O3:Eu3+ thin film was synthesized by sol-gel method with inorganic salt raw materials, and the crystal structure and luminescent properties were investigated. By adding organic additive to the sol, a homogeneous film with high luminescent intensity could be obtained by dip-coating technique on the surface of alumina sheet and quartz glass. Structures of the films were studied by XRD and SEM. The excitation spectra of the films showed a wide excitation peak from 200nm to 260nm, and the emission spectra had a strongest emission peak at 611nm which revealed a close relationship with the calcining temperature.


Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 259
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Tomasz Goryczka ◽  
Ewa Pietrasik ◽  
Wojciech A. Pisarski

The synthesis and characterization of multicolor light-emitting nanomaterials based on rare earths (RE3+) are of great importance due to their possible use in optoelectronic devices, such as LEDs or displays. In the present work, oxyfluoride glass-ceramics containing BaF2 nanocrystals co-doped with Tb3+, Eu3+ ions were fabricated from amorphous xerogels at 350 °C. The analysis of the thermal behavior of fabricated xerogels was performed using TG/DSC measurements (thermogravimetry (TG), differential scanning calorimetry (DSC)). The crystallization of BaF2 phase at the nanoscale was confirmed by X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM), and the changes in silicate sol–gel host were determined by attenuated total reflectance infrared (ATR-IR) spectroscopy. The luminescent characterization of prepared sol–gel materials was carried out by excitation and emission spectra along with decay analysis from the 5D4 level of Tb3+. As a result, the visible light according to the electronic transitions of Tb3+ (5D4 → 7FJ (J = 6–3)) and Eu3+ (5D0 → 7FJ (J = 0–4)) was recorded. It was also observed that co-doping with Eu3+ caused the shortening in decay times of the 5D4 state from 1.11 ms to 0.88 ms (for xerogels) and from 6.56 ms to 4.06 ms (for glass-ceramics). Thus, based on lifetime values, the Tb3+/Eu3+ energy transfer (ET) efficiencies were estimated to be almost 21% for xerogels and 38% for nano-glass-ceramics. Therefore, such materials could be successfully predisposed for laser technologies, spectral converters, and three-dimensional displays.


2007 ◽  
Vol 336-338 ◽  
pp. 585-588 ◽  
Author(s):  
Dao Qi Xue ◽  
Jun Ying Zhang ◽  
Hai Bing Feng ◽  
Tian Min Wang

ZnO:Eu3+ films were obtained by dip-coating method and influence of heat treatment on luminescent properties was investigated. Emission and excitation spectra revealed that the organic and nitrate molecules, which adhered on the surface of films when the samples were treated at lower temperatures (300oC-400oC), played an important role on the luminescent properties. At higher temperatures (500oC-800oC), the luminescence spectra of ZnO and Eu3+ were quite different with those treated at lower temperatures. Energy transferred from ZnO host to Eu3+ was obviously observed in the emission and excitation spectra. The luminescence mechanism was discussed briefly.


2012 ◽  
Vol 549 ◽  
pp. 487-490 ◽  
Author(s):  
Xin Mu Zhou ◽  
Yong Xiu Li

Cd1-xZnxSiO3:0.01 Mn2+phosphor was synthesized by sol-gel method. It was characterized by excitation, emission spectra and XRD. The luminescent properties show the phenomenon of energy transfer from the tetrahedral coordinated Mn2+ion to the octahedral coordinated Mn2+ion after exciting by ultraviolet light, which boost the performance of the phosphor. With the increasing of Zn2+in Cd1-xZnxSiO3:0.01 Mn2+phosphor, it was observed the excitation spectra broadened and a red shift in the emission spectra, which emission peak moved from 580nm to 589nm.


2016 ◽  
Vol 16 (4) ◽  
pp. 3468-3473
Author(s):  
Xu Li ◽  
Huaye Zhang ◽  
Aiwei Tang ◽  
Li Guan ◽  
Zhen Guo ◽  
...  

The paper discusses preparation and luminescent properties of Sr5SiO4Cl6:Eu2+ blue phosphor, which was synthesized by sol–gel method. The emission and excitation spectra, SEM, XRD and diffuse reflection of the fluorescent powder were measured. It was shown that the samples were single phase of Sr5SiO4Cl6 by the XRD patterns. The photoluminescence and excitation spectra of this phosphor were investigated. The phosphor excited by 278 nm light showed an asymmetric spectrum. The emission spectra can be separated into three distinct peaks located at 450, 480 and 540 nm, respectively. The influences of Eu2+ ions concentration on the emission intensity of Sr5SiO4Cl6:Eu2+ phosphors were studied in detail. The influences of different sintering temperature on the emission intensity were also investigated. The optimal sintering temperature was 750 °C. Effects of the amount of complexing agent were studied and a ratio of 1∼1.1 to that of the cation was the best. The particle diameter of the phosphor was studied by SEM. The potential applications were also discussed.


2015 ◽  
Vol 15 (10) ◽  
pp. 7765-7769 ◽  
Author(s):  
Sook Hyun Kwon ◽  
Byung Kee Moon ◽  
Jung Hyun Jeong ◽  
Hyun Kyoung Yang ◽  
Jung Hwan Kim

A series of 6 mol% Eu3+ doped Gd2MoO6 samples were prepared by using the sol–gel method. The X-ray diffraction patterns of the samples confirmed their monoclinic structure after they were annealed at 1300 °C, and a scanning electron microscope image revealed closely packed particles. The excitation spectra showed that the intensity of the excitation band decreased and the charge transfer band shifted from 370 to 350 nm with decreasing sintering temperature. The emission spectra are dominated by the hypersensitive forced electron dipolar transition 5D0 → 7F2 at 612 nm. The as synthesized phosphor can be used as a red phosphor in white light emitting diodes.


2013 ◽  
Vol 811 ◽  
pp. 181-185 ◽  
Author(s):  
Lan Tu Ya Wu

The rare-earth Eu3+doped BaY2O4red phosphor synthesized by citric acid sol-gel method. The structure, morphology and composition of the red phosphor were characterized by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The results show that the distribution of the pure phase BaY2O4: Eu3+particles after annealing at 800 °C was irregular, small size of particle is 0.2 μm to 0.4 μm. The excitation spectra of synthesized phosphor at 610 nm monitoring were composed of a broadband and a series of sharp peaks, the strongest excitation peak at 466 nm, the secondly at 395nm. It was indicated that BaY2O4: Eu3+phosphor matching with the widespread applied the output wavelengths of UV LED and blue LED chips. The main emission spectra of samples under blue light excitation is Eu3+ions5D07F2electric dipole transition with a strong red light, so that the BaY2O: Eu3+phosphor may be a better candidate for red component for white LED.


Author(s):  
Kaitao Yu ◽  
Lifang Wei ◽  
Jiaqi Shen

The series of luminescent materials of Eu3 +, Tb3 + doped Li2SrSiO4 were synthesized by a high-temperature solid-state method. The phase purity of the samples was measured by X-ray powder diffraction (XRD). The luminescent properties of the samples were studied by UV-visible excitation spectra and emission spectra The It is found that the strong absorption of Eu3 + doped Li2-xSr1-xEuxSiO4 is from the 250 ~ 290 nm charge transfer band of Eu3 + and the 7F0 → 5L6 absorption transition of 393 nm. The strongest emission of the emission spectra at 393 nm is 614 nm and 701 nm, respectively, from the 5D0 → 7F2 and 5D0 → 7F4 transitions of Eu3 +. Tb3 + doped sample Li2-xSr1-xTb xSiO4 excitation spectrum is mainly composed of Tb3 + ion fd transition and charge transfer band composed of broadband, the strongest absorption at 269 nm, the emission of the main emission of 5D4 → 7F5 transition (542 nm).


Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 148 ◽  
Author(s):  
P. Popielarski ◽  
J. Zeler ◽  
P. Bolek ◽  
T. Zorenko ◽  
K. Paprocki ◽  
...  

This work is dedicated to the preparation and characterization of the radio-, thermo-, and photoluminescent properties of Lu2O3:Eu and Lu2O3:Tb nanopowder (NPs) scintillators, prepared by means of hydrothermal processing, and their film analogues made of these NPs by the spin coating method. The luminescent properties of NPs and films were characterized by cathodoluminescence (CL), photoluminescence (PL), X-ray excited radioluminescence (RL), and thermoluminescence (TL) at low and high temperatures. In Lu2O3:Eu NPs and films, mostly the luminescence of Eu3+ ions occupying the C2 site of the host, with the most intensive peaks at 611.6 nm and a decay time of 1.5 ms, was observed. On the contrary, two types of Tb3+ centers in the C2 and C3i sites with the main emission lines at 542.4 and 544.0 nm and the corresponding 4f→5d excitation bands at 270 and 305 nm and decay times of t1/e = 2.17 and 3.96 ms were observed in the case of Lu2O3:Tb NPs and films. Indications were noted that Tb3+ in the C3i symmetry position was most active in the CL spectra of Lu2O3:Tb NPs and a respective film. Thermoluminescent peaks at 110 °C and 170 °C for Lu2O3:Eu NPs and at 75 °C and 120 °C in Lu2O3:Tb NPs were observed corresponding to the hole and electron traps, respectively. Significantly different onsets of temperature quenching of Eu3+ and Tb3+ luminescence in Lu2O3:Eu and Lu2O3:Tb NPs were found at ~90 °C and ~320 °C, respectively.


2001 ◽  
Vol 15 (17n19) ◽  
pp. 769-773 ◽  
Author(s):  
M. GARCIA-ROCHA ◽  
A. CONDE-GALLARDO ◽  
I. HERNANDEZ-CALDERON ◽  
R. PALOMINO-MERINO

In this work we show the results on tile growth and optical characterization of TiO 2 thin films doped with Eu atoms. Eu:TiO2 films were grown at room temperature with different Eu concentrations by sol-gel on Si Corning glass substrates. A different crystalline structure is developed for the films deposited on Corning glass than those deposited on Si as observed from x-ray diffraction experiments. Room and low temperature photoluminescence (PL) was measured by using two different lines (325 and 442 nm) of a HeCd laser. A strong PL signal associated to the 5 D 0→7 F 2 transition from Eu +3 was observed. A better emission was obtained from those films deposited on Si substrates, Finally, the evolution of the PL signal is studied when the samples are annealed at different temperatures in O 2 atmosphere.


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