粉末内部:MgO纳米晶体之间的接口的理论模型
Keith P McKenna1, Peter V Sushko, Alexander L Shluger
1Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK. k.mckenna@ucl.ac.uk
Journal of the American Chemical Society
|June 16, 2007
概括
这项研究揭示了电子和孔如何与氧化 (MgO) 纳米晶体界面相互作用. 孔更喜欢被困在表面离子上,而电子更喜欢表面缺陷,影响MgO的光学特性.
科学领域:
- 材料科学 材料科学 材料科学
- 量子化学 是一个量子化学.
- 表面科学是一门学科.
背景情况:
- 了解纳米晶体界面对于材料应用至关重要.
- 电子和孔陷机制影响材料的特性.
- 氧化 (MgO) 纳米晶体具有不同的潜在应用.
研究的目的:
- 为了研究MgO纳米晶体界面的电子和陷孔特性.
- 为了探索MgO纳米晶体界面的光学特性.
- 提供对MgO粉末中电荷载体行为的基本理解.
主要方法:
- 使用量子力学嵌入式集群方法.
- 采用了时间依赖密度函数理论 (TD-DFT).
- 计算的光学吸收光谱.
主要成果:
- 不定位的孔可以暂时被困在MgO粉中.
- 孔最好在纳米晶体表面的低协调离子 (O-) 上捕获.
- 电子在接口上被捕获,特别是在表面曲和角位.
- 光学吸收光谱表明埋藏的特征在<5 eV的激发.
结论:
- 洞陷对表面离子 (O-) 在能量方面有利.
- 电子陷定位在特定的接口缺陷点.
- MgO纳米晶体表现出可在低光子能量的光学吸收特征比通常假设.
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