Title of Paper:Synthesis and luminescence enhancement of CaySr4-x-yAl2O7:xEu(2+) phosphors by a novel halide-assisted solid-state reaction method

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Affiliation of Author(s):材料科学与技术学院

Journal:JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS

Key Words:RED-EMITTING PHOSPHORS NANOCRYSTALLINE HYDROXYAPATITE LEDS IONS PHOTOLUMINESCENCE OXYNITRIDE MAGNESIUM EMISSION POWDERS DIODES

Abstract:Eu2+ doped strontium aluminate phosphors CaySr4-x-yAl2O7:xEu(2+) (0 x 0.1, 0 y 0.1) were synthesized via a novel halide-assisted solid-state reaction method. The phase structure and photoluminescence properties of CaySr4-x-yAl2O7:xEu(2+) were characterized via X-ray diffraction (XRD) and fluorescence spectrophotometer. The XRD patterns indicate that the alpha-Sr4Al2O7 phase structure with negligible impurities were produced in the samples of CaySr4-x-yAl2O7:xEu(2+) (x 0.1 and y 0.1) at 1450 A degrees C. Photoluminescence results show that the CaySr4-x-yAl2O7:xEu phosphor with NH4I as reductant presents typical intense Eu2+ red emission bands centered at 610 nm while excited by 450 nm. Accordingly, samples without NH4I only exhibit two weak Eu3+ emission peaks located at 598 and 619 nm, respectively. It can be ascribed to the reduction characteristic of I- ion. Furthermore, by partial replacement of Sr2+ with Ca2+ in Sr4Al2O7 host, the emission intensity is enhanced up to 260% with emission peak red shifted by 5-10 nm. These results indicate that partial substitution of Sr2+ by Ca2+ is an efficient way to increase the proportion of longer wavelength emission and luminescence intensity for Sr4Al2O7:Eu phosphors.

ISSN No.:0957-4522

Translation or Not:no

Date of Publication:2018-06-01

Co-author:He, Qinjiang,Zhu, Haitao,He, Hong,Song, Xiufeng,Liu, Xuhai

Correspondence Author:frl