Photoluminescence and thermal quenching properties of tunable green-emitting oxynitride (Ca_xSr_1-x)₆Si_25.6Al_6.4N_41.6O_4.4:Eu²⁺ phosphors

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• 作者：Chunlei ZHAO ((赵春雷))^a ; ^b ; Qian MA ((马 谦))^a ; ^b ; Huibing XU ((徐会兵))^b ; Kai CHEN ((陈 凯))^b ; Yunsheng HU ((胡运生))^b ; Hongqi YE ((叶红))^a ; ^{yeslab@csu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Ronghui LIU ((刘荣辉))^b ; ^{griremlrh@126.com" class="auth_mail" title="E-mail the corresponding author} ; Yuanhong LIU ((刘元红))^b ; Xiaofang ZHOU ((周小芳))^b
• 关键词：oxynitride phosphors ; green emitting ; white LEDs ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：34
• 期：5
• 页码：470-474
• 全文大小：929 K

文摘

Green emitting Eu²⁺ doped (Ca_xSr_1–x)₆Si_25.6Al_6.4N_41.6O_4.4 phosphors with x value ranging from 0 to 0.1 were synthesized by the solid state reaction method under nitrogen atmosphere. The X-ray diffraction (XRD) patterns of the phosphors with different Ca²⁺ concentrations indicated that pure sialon phases were obtained. Crystal structure of these sialon phases was estimated to be a commensurate composite network stacking by two different types of layers. Intense and tunable green emissions with a slight red shift from 515 to 520 nm were observed with varying Ca/Sr ratios. The emission intensity decreased gradually because of the increase of the crystal splitting effect. Thermal quenching properties of the phosphors with different Ca²⁺ saturation were also discussed. The thermal stability became worse as more Ca²⁺ ions substituted for Sr²⁺ ions according to a larger Stokes shift. The solid solution phosphors could be a promising candidate for white LEDs for their interesting photoluminescence properties when the thermal stability would be improved.