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In this paper, we report on fabricating optical fibers with a controlled process of crystallization core during the drawing process. The research and synthesis of the core material of silica-germanium-antimony oxide glass were discussed. We also investigated the optical and luminescence properties were in relation to concentrating Eu 2 O 3 and P 2 O 5. Based on this investigation, we selected the most promising material for optical fiber core. In the next step, we drew optical fibers using a well-known rod-in-tube method. After drawing, we examine the optical fibers for luminescence shape changes. We observed a promising similarity between optical fibers and heat-treated samples with confirmed nanocrystals. Finally, XRD and TEM measurements confirm EuPO 4 nanocrystals at the core of the optical fiber. Highlighting the successful control of crystallization in the one-step method used to draw optical fibers. [ABSTRACT FROM AUTHOR]

Functional materials exhibiting polymorphism serve as excellent candidates for various optical applications since the properties can be tuned to the desired target/application by modifying the structural features. Herein, we explored the synthesis of Eu3+ doped gadolinium oxyfluoride systems via a green microwave-assisted hydrothermal method, and phase controllability was established by varying the O2− to F- ratio. The phase evolution and crystal structure of the Eu3+ doped oxyfluoride analogs were examined using Rietveld refinement studies, and the results were consistent with the site symmetries unveiled by the photoluminescence spectra of Eu3+. The low phonon energy of all the phosphors, calculated from the Raman spectra, suggested the possibility of these groups of materials as excellent host matrices for optical applications. Further, a drastic variation in the morphology of studied oxyfluorides at different phases is evidenced by the electron microscopic analysis. The highly asymmetric rhombohedral sites enhanced the color purity, lifetime, and quantum yield of the red phosphor, making it an excellent red component for the fabrication of UV-excitable red as well as white light-emitting diodes for lighting and display device functionalities. [ABSTRACT FROM AUTHOR]

In the recent decade, various potential applications of the luminescence of nanosized ZrO 2 :Eu3+ have been demonstrated. However, the particle size effect on the luminescence properties of ZrO 2 :Eu3+ still requires intensive investigation. To this end, a series of tetragonal ZrO 2 :Eu3+ nanopowders with the europium concentration of 4 wt% and particle size of 3.0 ± 0.7 to 12.0 ± 4.8 nm was synthesized by laser vaporization. It was shown that the dominant role in the optical properties of ZrO 2 :Eu3+ nanoparticles belongs to OH groups, oxygen vacancies, and Eu3+ ions. It was found that a decrease in the particle size is accompanied by a significant increase in the emission intensity in the region of ∼440 nm. Based on the results of thermal analysis, IR and UV–vis DR spectroscopies, it was concluded that this luminescence is due to the emission of adsorbed OH groups. At the same time, a decrease in the number of vacancies with a decrease in the particle size leads to a change in the absolute quantum yield QY from ∼7 to 3.5%. In addition, despite the overall decrease in the intensity of the red luminescence of Eu3+, a decrease in the particle size leads to the appearance and increase in the emission intensity of the surface Eu3+. Thus, changing the particle size from 12.0 to 3.0 nm leads to a twofold decrease in the luminescence efficiency of ZrO 2 :Eu3+ and a shift in the color of its emission from pink-red (0.36, 0.26) to blue (0.19, 0.10). The results obtained are expected to be useful for further optimization of the luminescence properties of nanosized ZrO 2 :Eu3+ in numerous applications. [ABSTRACT FROM AUTHOR]