Optical Properties of Ba2-XSrxSiO4: Eu2+, Dy3+ Phosphors and their Applications for White LED

2012 ◽  
Vol 529 ◽  
pp. 154-158
Author(s):  
Mei Zhang ◽  
Ping Wang ◽  
Xin He ◽  
Qing Guang Zeng ◽  
Jin Xiu Wen

A series of Ba1.91-xSrxSiO4:Eu2+, Dy3+phosphors were synthesized by the high-temperature solid-state reaction. The structure of powder samples were characterized by X-ray powder diffraction. The photoluminescence emission and excitation spectra are also studied. It can be proved the formation of the solid solution of Ba1.91-xSrxSiO4:Eu2+, Dy3+ compounds, and the phosphors can be efficiently excited by UV-visible light from 300 to 480 nm. The as-synthesized Ba1.91-xSrxSiO4:Eu2+, Dy3+ phosphors are promising candidates applicable to near-UV and blue LEDs for solid-state lighting.

2002 ◽  
Vol 755 ◽  
Author(s):  
Damien Pauwels ◽  
Alain Demourgues ◽  
Alain Tressaud

ABSTRACTRare earth-based mixed-anions (O, S, F) compounds have been prepared by solid state route. The structures have been determined on the basis of powder diffraction (X-ray/neutrons) refinement and/or single crystal analysis. They have been described as a stacking of [Sx] 2x- layers and fluorite type blocks. The evaluation of the rare earth environment (bondlength, number of neighbors) can be directly related to the bandgap and to the UV-visible absorption in the La-based compounds.


2018 ◽  
Vol 73 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Lu Pan ◽  
Xiaozhan Yang ◽  
Chaoyue Xiong ◽  
Dashen Deng ◽  
Chunlin Qin ◽  
...  

AbstractA series of new red-orange emission phosphors Na2BaMg(PO4)2:Pr3+ were synthesised by a high-temperature solid-state reaction. The crystal structure and photoluminescence properties of these samples were characterised by X-ray diffraction and spectroscopic measurements. This compound holds P3̅m1 space group of the trigonal system with the lattice parameters of hexagonal cell a=0.5304(3) nm and c=0.6989(3) nm. The phosphor emits the strongest peak at 606 nm when excited by 449 nm. The average Commission Internationale de l’Eclairage chromaticity coordinates calculated for the phosphors are (0.52, 0.46). The results demonstrate the potential application of these phosphors in solid-state lighting and other fields.


Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 153 ◽  
Author(s):  
Mahdi Kiani Khouzani ◽  
Abbas Bahrami ◽  
Maryam Yazdan Mehr ◽  
Willem Dirk van Driel ◽  
Guoqi Zhang

This paper aims to investigate the synthesis, structure, and optical properties of SiO2@YAG:Ce core–shell optical nanoparticles for solid state lighting applications. YAG:Ce phosphor is a key part in white light emitting diodes (LEDs), with its main functionality being the generation of yellow light. Generated yellow light from phosphor will be combined with blue light, emitted from chip, resulting in the generation of white light. Generated light in LEDs will often be scattered by SiO2 nanoparticles. SiO2 nanoparticles are often distributed within the optical window, aiming for a more homogeneous light output. The main idea in this research is to combine these functionalities in one core–shell particle, with its core being SiO2 and its shell being phosphor. In this study core–shell nanoparticles with different Ce3+ concentrations were synthesized by a sol–gel method. Synthesized nanoparticles were characterized by X-ray diffraction (XRD), small angle X-ray scattering (SAXS) analysis, high resolution transmission electron macroscopy (HRTEM), Fourier transform infrared (FTIR), and photoluminescence spectroscopy. Luminescence characteristics of SiO2@YAG:Ce core–shell particles were compared with that of SiO2/YAG:Ce mixture composite, which is now used in commercial LEDs. Obtained results showed that core–shell nanoparticles have comparatively much better optical properties, compared to SiO2/YAG:Ce mixture composite and can therefore be potentially used in LEDs.


2014 ◽  
Vol 2 (30) ◽  
pp. 6084 ◽  
Author(s):  
Naoyuki Komuro ◽  
Masayoshi Mikami ◽  
Yasuo Shimomura ◽  
Erica G. Bithell ◽  
Anthony K. Cheetham

2021 ◽  
Author(s):  
Jing Yan ◽  
Chunyan Jiang ◽  
Yulun Xian ◽  
Jianbang Zhou ◽  
Hong Li ◽  
...  

A series of Tb3+- and Eu3+-doped Ca8ZnLu(PO4)7 (CZLP:Tb3+ and CZLP:Eu3+) as well as Ca8ZnTb(PO4)7:Eu3+ (CZTP:Eu3+) phosphors have been prepared via the traditional high-temperature solid-state reaction. X-ray powder diffraction (XRD) patterns...


2014 ◽  
Vol 700 ◽  
pp. 113-116
Author(s):  
Yu Jie Chen ◽  
Feng Lan Han ◽  
Zhao Luo

Na2BaMgP2O8phosphors were synthesized by a standard solid state reaction and their luminescent properties were investigated. The phase structure was analyzed by X-ray powder diffraction measurement. Under the excitation of 365nm, Na2BaMgP2O8:Tb3+, Eu3+phosphors show two color bands of green and red color due to5D4−7F5transition of Tb3+ions and5D0−7F2transition of Eu3+ions, respectively. The emission intensity of Tb3+deceased with the increasing concentration of Eu3+, which verified that an effective energy transfer occurred from Tb3+to Eu3+in Na2BaMgP2O8host. The present study indicated that the phosphors have a high potential application in solid state lighting.


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).


2013 ◽  
Vol 770 ◽  
pp. 225-228
Author(s):  
L. Uttayan ◽  
K. Aiempanakit ◽  
M. Horprathum ◽  
P. Eiamchai ◽  
V. Pattantsetakul ◽  
...  

Titanium dioxide (TiO2) films were prepared by thermal oxidation from Ti films. The Ti films were deposited on glass and silicon (100) wafer substrate by dc magnetron sputtering and subsequent with thermal oxidation process. The crystal structure and morphology of TiO2 films were estimated by using X-ray diffractometry (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The optical property of TiO2 films was determined by UV-Visible spectrophotometer. The influences of annealing temperature between 200 to 500°C in air for 1 hour on the structure and optical properties of TiO2 films were investigated. The increasing of annealing temperature was directly affected the phase transition from Ti to TiO2. The optical and structural properties of TiO2 films are the best exhibited with increasing the annealing temperature at 500 °C.


2018 ◽  
Vol 74 (5) ◽  
pp. 623-627 ◽  
Author(s):  
Sviatoslav Baranets ◽  
Hua He ◽  
Svilen Bobev

Three isostructural transition-metal arsenides and germanides, namely niobium nickel arsenide, Nb0.92(1)NiAs, niobium cobalt arsenide, NbCoAs, and niobium nickel germanide, NbNiGe, were obtained as inadvertent side products of high-temperature reactions in sealed niobium containers. In addition to reporting for the very first time the structures of the title compounds, refined from single-crystal X-ray diffraction data, this article also serves as a reminder that niobium containers may not be suitable for the synthesis of ternary arsenides and germanides by traditional high-temperature reactions. Synthetic work involving alkali or alkaline-earth metals, transition or early post-transition metals, and elements from groups 14 or 15 under such conditions may yield Nb-containing products, which at times could be the major products of such reactions.


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