On the Origin and Structure of the First Sharp Diffraction Peak of Amorphous Silicon
On the Origin and Structure of the First Sharp Diffraction Peak of Amorphous Silicon
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DOI：
10.1002/pssb.202000447
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发表时间：
2021-01-27
影响因子：
1.6
通讯作者：
Biswas, Parthapratim
中科院分区：
文献类型：
--
作者：
Dahal, Devilal;Warren, Hiroka;Biswas, Parthapratim
讨论了非晶硅（a-Si）在2埃（-1）附近的第一个尖锐衍射峰（FSDP）的结构，着重讨论了衍射曲线的位置、强度和宽度。通过对a-Si的连续无规网络（CRN）模型的研究表明，FSDP的位置和强度主要取决于15埃尺度上非晶网络中原子的径向关联。对不同径向壳贡献的逐壳分析表明，对FSDP的关键贡献来自网络中的第二和第四径向壳，伴随着来自第一壳的背景贡献和来自远处径向壳的小的残余修正。从数值计算的结果是补充的唯象讨论的结构因子在波矢量空间和减少对相关函数在真实的空间中的峰之间的关系。导出了FSDP的位置与网络中第二径向壳层中Si原子平均径向距离之间的近似函数关系，并通过数值计算得到了证实.
The structure of the first sharp diffraction peak (FSDP) of amorphous silicon (a-Si) near 2 angstrom(-1) is addressed with particular emphasis on the position, intensity, and width of the diffraction curve. By studying a number of continuous random network (CRN) models of a-Si, it is shown that the position and intensity of the FSDP are primarily determined by radial atomic correlations in the amorphous network on the length scale of 15 angstrom. A shell-by-shell analysis of the contribution from different radial shells reveals that key contributions to the FSDP originate from the second and fourth radial shells in the network, which are accompanied by a background contribution from the first shell and small residual corrections from the distant radial shells. The results from numerical calculations are complemented by a phenomenological discussion of the relationship between the peaks in the structure factor in the wavevector space and the reduced pair-correlation function in the real space. An approximate functional relation between the position of the FSDP and the average radial distance of Si atoms in the second radial shell in the network is derived, which is corroborated by numerical calculations.