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在氧化化的光发光的阴离子大小不匹配调整
Wei-Ting Chen1, Hwo-Shuenn Sheu, Ru-Shi Liu
1Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
Journal of the American Chemical Society
|April 27, 2012
概括
调整白光应用中的的特性是关键. 在M{1.95) Eu{0.05) Si{5-x) Al{x) N{8-x) O{x) 格子中的阴离体大小不匹配,通过拟议的离子聚合机制,系统地转移光发和热火.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 发光的阴影是什么意思
背景情况:
- 用于LED的白光生成通常使用由蓝光激发的红色或黄色光.
- 基于化的材料 (例如,M(2) Si(5) N(8),MSi(2) O(2) N(2),CaAlSiN(3),SiAlON) 是稳定的宿主.
- 通过阴离子替代调节发光性质是常见的,但机制尚未完全理解.
研究的目的:
- 研究阴离体大小不匹配对M(1.95) Eu(0.05) Si(5-x) Al(x) N(8-x) O(x) 格子中的光发光位移的影响.
- 探索尺寸不匹配对热火性能的影响.
- 阐明了导致这些观察到效应的潜在机制.
主要方法:
- 合成和特征的M{1.95) Eu{0.05) Si{5-x) Al{x) N{8-x) O{x) 和不同的M离子 (Ca, Sr, Ba).
- 光发光光谱学用于分析辐射光谱和转移.
- 热灭测量以评估在高温下发光的稳定性.
主要成果:
- 观察到系统的光发光变化,与宿主 (M) 和剂 (Eu(2+)) 子之间的尺寸差异相关.
- 当M离子 (Ba,Sr) 大于Eu{2+) 时发生红色转移,而当M离子 (Ca) 较小时发生蓝色转移.
- 尺寸不匹配也影响了热火,对于不同的M cation观察到不同的效果.
结论:
- 阴离子尺寸不匹配是调整这些氧化酸的光发光和热火的关键因素.
- 建议使用局部离子聚合机制,涉及Eu2+的化物/氧化物差异协调,以解释观察到的不匹配效应.
- 这种机制为优化对局部协调敏感的氧化物材料的光学和其他特性提供了总体策略.
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