Department of Physics, University of Texas at Arlington, Arlington, Texas 76019, USA.
Department of Physics and Astronomy, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, USA.
J Chem Phys. 2018 May 28;148(20):204503. doi: 10.1063/1.5021813.
It is widely accepted in the materials modeling community that defect-free realistic networks of amorphous silicon cannot be prepared by quenching from a molten state of silicon using classical or ab initio molecular-dynamics (MD) simulations. In this work, we address this long-standing problem by producing nearly defect-free ultra-large models of amorphous silicon, consisting of up to half a million atoms, using classical MD simulations. The structural, topological, electronic, and vibrational properties of the models are presented and compared with experimental data. A comparison of the models with those obtained from using the modified Wooten-Winer-Weaire bond-switching algorithm shows that the models are on par with the latter, which were generated via event-based total-energy relaxations of atomistic networks in the configuration space. The MD models produced in this work represent the highest quality of amorphous-silicon networks so far reported in the literature using MD simulations.
在材料建模领域，人们普遍认为，无法通过使用经典或从头算分子动力学 (MD) 模拟从熔融硅中淬火来制备无缺陷的真实非晶硅网络。在这项工作中，我们通过使用经典 MD 模拟生成了近无缺陷的超大型非晶硅模型（多达五十万个原子），从而解决了这一长期存在的问题。本文介绍了模型的结构、拓扑、电子和振动特性，并与实验数据进行了比较。将模型与通过修改的 Wooten-Winer-Weaire 键切换算法获得的模型进行比较表明，与后者相比，模型与后者相当，后者是通过在构型空间中对原子网络进行基于事件的总能量松弛生成的。本工作中生成的 MD 模型代表了迄今为止使用 MD 模拟在文献中报道的非晶硅网络的最高质量。
