Highly Stable Red-Emitting Sr₂Si₅N₈:Eu²⁺ Phosphor with a Hydrophobic Surface

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• 作者：Bi Zhang ; Jun-Wei Wang ; Lu-Yuan Hao ; Xin Xu ; Simeon Agathopoulos ; Liang-Jun Yin ; Cheng-Ming Wang and Hubertus T. (Bert) Hintzen
• 刊名：Journal of the American Ceramic Society
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：100
• 期：1
• 页码：257-264
• 全文大小：1954K
• ISSN：1551-2916

文摘

One of the biggest problems in white light-emitting diodes (WLEDs) is the moisture-induced degradation of phosphors. This paper proposes a simple and feasible surface modification method to solve it, whereby a hydrophobic surface layer is developed on the surface of the phosphors. The particular case of orange-red-emitting Sr₂Si₅N₈:Eu²⁺ (SSN) phosphor was investigated. The mechanism to develop the hydrophobic layer involves hydrolysis and polymerization of tetraethylorthosilicate (TEOS) and polydimethylsiloxane (PDMS). The experimental results showed that the surface layer of SSN phosphor was successfully modified to a hydrophobic nanolayer (8 nm) of amorphous silicon dioxide that contains CH₃ groups in the surface. This hydrophobic surface layer gives the modified phosphor superior stability in high-pressure water steam conditions at 150°C.