Structural and electronic properties of p-doped silicon clathrates
Structural and electronic properties of p-doped silicon clathrates
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DOI：
10.1103/physrevb.75.125202
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发表时间：
2007-03
影响因子：
3.7
通讯作者：
D. Connétable
中科院分区：
文献类型：
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作者：
D. Connétable
我们提出了一个从头算研究的结构和电子性质的类型-I和类型-II的硅笼形物掺杂的元素选择是电负性比硅。根据插入的元素，我们表明，掺杂的硅笼形物的电子性质可以表现出金属，半导体，或绝缘行为。特别地，发现掺杂可以导致硅基材料具有可见光范围内的带隙，并且在II型笼形物中，差距可以是直接的。然而，选择规则的分析表明，光学跃迁是禁止在I型和II型笼形物。关于结构性质，掺杂剂原子和硅之间的键合可以显著地将主体网络的可压缩性降低到与更致密的金刚石相的值相当的值。通过对硅团簇SinHn n= 20，24，28的研究，对上述结果进行了补充和合理化.
We present an ab initio study of the structural and electronic properties of type-I and type-II silicon clathrates doped by elements chosen to be more electronegative than silicon. Depending on the intercalated element, we show that the electronic properties of doped silicon clathrates can exhibit metallic, semiconducting, or insulating behavior. It is found in particular that doping can lead to silicon-based materials with a band gap in the visible range and that, in type-II clathrates, the gap can be direct. However, the analysis of the selection rules show that the optical transitions are forbidden in type-I and type-II clathrates. Concerning the structural properties, the bonding between the dopant atom and silicon can significantly decrease the compressibility of the host network to values equivalent to the one of the much denser diamond phase. The present results are complemented and rationalized by the study of endohedrally doped SinHn n=20,24,28 silicon clusters.