Correlation between the band gap, elastic modulus, Raman shift and melting point of CdS, ZnS, and CdSe semiconductors and their size dependency.
Correlation between the band gap, elastic modulus, Raman shift and melting point of CdS, ZnS, and CdSe semiconductors and their size dependency.
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DOI：
10.1039/c2nr11605g
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发表时间：
2012-02
期刊：
影响因子：
6.7
通讯作者：
C. Yang;Zhaofeng Zhou;J. Li;X. X. Yang-X.;W. Qin;R. Jiang;N. Guo;Yan Wang;Changqing Sun;Changqing Sun
中科院分区：
文献类型：
--
作者：
C. Yang;Zhaofeng Zhou;J. Li;X. X. Yang-X.;W. Qin;R. Jiang;N. Guo;Yan Wang;Changqing Sun;Changqing Sun
随着结构小型化到纳米级，固体材料的可检测量不再保持恒定，而是变得可调。对于II-VI族半导体的例子，带隙扩大，弹性模量增加，熔点下降，并且拉曼光学声子经历与低频拉曼声学模式的产生相关联的红移，所述低频拉曼声学模式随着尺寸尺度的减小而经历蓝移。为了了解这些看似无关的属性的大小依赖性的共同起源，我们制定了这些量的CdS，ZnS和CdSe半导体的键级长度强度相关性和本地键平均方法的角度。理论预测与这些量的测量尺寸依赖性之间的一致性澄清了欠配位引起的局部应变和量子俘获以及整个固体中欠配位原子的不同比例与这些量相关并主导其尺寸效应。
With structural miniaturization down to the nanoscale, the detectable quantities of solid materials no longer remain constant but become tunable. For the II-VI semiconductors example, the band gap expands, the elastic modulus increases, the melting point drops, and the Raman optical phonons experience red shift associated with creation of low frequency Raman acoustic modes that undergo blue shift with decreasing the dimensional scale. In order to understand the common origin of the size dependency of these seemingly irrelevant properties, we formulated these quantities for CdS, ZnS, and CdSe semiconductors from the perspectives of bond order-length-strength correlation and the local bond averaging approach. Consistency between the theory predictions and the measured size dependence of these quantities clarified that the undercoordination-induced local strain and quantum entrapment and the varied fraction of undercoordinated atoms of the entire solid correlate these quantities and dominate their size effect.