WIDE-BAND-GAP SI IN OPEN FOURFOLD-COORDINATED CLATHRATE STRUCTURES
WIDE-BAND-GAP SI IN OPEN FOURFOLD-COORDINATED CLATHRATE STRUCTURES
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DOI：
10.1103/physrevb.49.8048
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发表时间：
1994-03-15
影响因子：
3.7
通讯作者：
HUANG, YM
中科院分区：
文献类型：
--
作者：
ADAMS, GB;OKEEFFE, M;HUANG, YM
研究了两种四配位包络结构中元素半导体Si的能级结构和能带结构。对于Si(34)和Si(46)结构，我们预测间接带隙接近1.9 eV，或比众所周知的SP3钻石结构中的Si宽0.7 eV。我们发现包络结构和金刚石结构之间的能量差约为0.07 eV，比更紧凑的高压结构的硅的能量差小近三倍。计算采用从头算紧束缚类分子动力学方法，并用完全自洽的平面波方法进一步校核。从应变能的角度讨论了包层结构和金刚石结构中硅之间能量差异较小的可能原因。我们将硅的结果与含有碳的类似结构的结果进行了比较。
The energetics and band structures of the elemental semiconductor Si in two fourfold-coordinated clathrate structures have been studied. For the Si(34) and Si(46) structures we predict indirect band gaps near 1.9 eV, or 0.7 eV wider than that of Si in the well-known sp3 diamond structure. We find that the energy differences between the clathrate structures and the diamond structure are about 0.07 eV, which is nearly three times smaller than those for more compact high-pressure structures of Si. The calculations are done using an ab initio tight-binding-like molecular-dynamics method, and further checked by the fully self-consistent plane-wave method. The possible origin of the small energy differences between Si in the clathrate and diamond structures is discussed in terms of strain energy. We compare the results for Si with those for similar structures involving carbon.