Influence of disorder on the electronic structure of amorphous silicon
Influence of disorder on the electronic structure of amorphous silicon
复制标题
无序对非晶硅电子结构的影响
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
Jasprit Singh
中科院分区：
文献类型：
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作者：
Jasprit Singh
我们已经使用连续随机网络中所有第一和第二个邻近耦合的紧密结合方案检查了无定形硅的电子结构。矩阵元素和变形电位是从晶带结构中获取的。键长和键角变化的影响相对较小，并有助于带边缘的狭窄尾巴。检查了二面角疾病的作用，仅保留了哈密顿量中最近的邻居相互作用。发现二面角疾病在价边缘很重要，并负责在价带顶部的观察到的特征。发现拓扑障碍在大部分带和传导带边缘都有重要的后果。除了键长和键角障碍的影响外，带边缘的状态局限于局部紧密接近晶体结构的区域，在该区域中，它们具有与晶体相同的形式，但不会延伸整个整个晶体结构。
We have examined the electronic structure of amorphous silicon using a tight-binding scheme with all first- and second-neighbor couplings in a continuous random network. Matrix elements and deformation potentials were taken from the crystalline band structure. The effect of bond-length and bond-angle variations is relatively small and contributes to the narrow tails at the band edges. The effect of dihedral-angle disorder was examined keeping only the nearest-neighbor interactions in the Hamiltonian. The dihedral-angle disorder was found to be important at the valence-band edge and responsible for the observed features near the top of the valence band. Topological disorder was found to have important consequences in the bulk of the bands as well as at the conduction-band edge. Apart from the effects of the bond-length and bond-angle disorder, the states at the band edges are confined within regions closely approaching the crystalline structure locally, where they have the same form as in the crystal, but do not extend through the entire structure.