Disorder by design: A data-driven approach to amorphous semiconductors without total-energy functionals
Disorder by design: A data-driven approach to amorphous semiconductors without total-energy functionals
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DOI：
10.1038/s41598-020-64327-3
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发表时间：
2019-12
影响因子：
4.6
通讯作者：
D. Limbu;S. Elliott;R. Atta-Fynn;P. Biswas
中科院分区：
文献类型：
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作者：
D. Limbu;S. Elliott;R. Atta-Fynn;P. Biswas
X射线衍射，非晶硅，多目标优化，蒙特卡罗方法。本文讨论了一个困难的逆问题，该问题涉及到通过衍射数据的反演来重建四面体非晶半导体的三维模型。通过将材料结构的确定问题归结为一个多目标优化问题，结果表明，只需少量的结构约束，而不需要描述非晶态网络局域化学的总能量泛函/力，就可以很好地解决这个问题。这种方法产生了高度逼真的非晶硅模型，没有或只有很少的配位缺陷(≤1%)，窄的键角分布宽度9-11.5°，电子能隙0.8-1.4 eV。这些数据驱动的基于信息的模型已经被发现能够产生与实验数据精确匹配的a-Si的电子和振动特性，并且可以与Wooten-Winer-Weaire模型相媲美。这项研究证实了多目标优化方法在复杂材料结构确定中的有效性，并解决了一个长期存在的关于由衍射数据反演得到的四面体非晶态半导体模型的唯一性的争论。
X-ray diffraction, Amorphous silicon, Multi-objective optimization, Monte Carlo methods. This paper addresses a difficult inverse problem that involves the reconstruction of a three-dimensional model of tetrahedral amorphous semiconductors via inversion of diffraction data. By posing the material-structure determination as a multiobjective optimization program, it has been shown that the problem can be solved accurately using a few structural constraints, but no total-energy functionals/forces, which describe the local chemistry of amorphous networks. The approach yields highly realistic models of amorphous silicon, with no or only a few coordination defects (≤1%), a narrow bond-angle distribution of width 9–11.5°, and an electronic gap of 0.8–1.4 eV. These data-driven information-based models have been found to produce electronic and vibrational properties ofa-Si that match accurately with experimental data and rival that of the Wooten-Winer-Weaire models. The study confirms the effectiveness of a multiobjective optimization approach to the structural determination of complex materials, and resolves a long-standing dispute concerning the uniqueness of a model of tetrahedral amorphous semiconductors obtained via inversion of diffraction data.