Moisture-induced degradation and its mechanism of (Sr, Ca)AlSiN3:Eu2+, a red-color-converter for solid state lighting. Issue 13 (18th February 2015)

• Record Type: Journal Article
• Authors: Zhu, Jie; Wang, Le; Zhou, Tianliang; Cho, Yujin; Suehiro, Takayuki; Takeda, Takashi; Lu, Ming; Sekiguchi, Takashi; Hirosaki, Naoto; Xie, Rong-Jun
• Is Part Of: Journal of materials chemistry. Volume 3:Issue 13(2015)
• Page Start: 3181
• Page End: 3188
• Publication Date: 2015-02-18
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c4tc02824d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The degradation of (Sr, Ca)AlSiN3 :Eu 2+ induced by the water steam attack results in remarkable changes in luminescence, microstructure and phase purity. Abstract : (Sr, Ca)AlSiN3 :Eu 2+ (SCASN) is a very promising red phosphor used as a down-conversion luminescent material in solid state lighting. In this study, the moisture-induced degradation of SCASN was comprehensively investigated by treating it under severe conditions with high-pressure water steam. The degradation initiated at 150 °C, and the luminescence of SCASN was quenched quickly, with the powder sample being bleached after the treatment. Both the microstructure and phase changed obviously with oxidation, and the host turned finally into NH3, (Sr, Ca)Al2 Si2 O8 and Ca(OH)2 . Using a variety of spectroscopic, surface and microstructure analytical techniques, the degradation mechanism was clarified and proposed to occur via the oxidant-gas penetration mechanism through the moisture-enhanced oxidation of both the SCASN host and divalent europium. The activation energy for the moisture-induced degradation was about 66.32 kJ mol −1 .