Title

Large and Realistic Models of Amorphous Silicon

Document Type

Article

Publication Date

7-15-2018

Department

Physics and Astronomy

Abstract

Amorphous silicon (a-Si) models are analyzed for structural, electronic and vibrational characteristics. Several models of various sizes have been computationally fabricated for this analysis. It is shown that a recently developed structural modeling algorithm known as force-enhanced atomic refinement (FEAR) provides results in agreement with experimental neutron and X-ray diffraction data while producing a total energy below conventional schemes. We also show that a large model (∼ 500 atoms) and a complete basis is necessary to properly describe vibrational and thermal properties. We compute the density for a-Si, and compare with experimental results.

Graphical Abstract

Color code: green (four-fold coordinated), salmon (over/under coordinated).

Figure: (Top panel, left): A random configuration of 512 silicon atoms in a supercell. (Top panel, right): Same random coordinates after inversion with FEAR. (Bottom panel): Comparison of structural and vibrational properties for different FEAR models with experimental results.

Publication Title

Journal of Non-Crystalline Solids

Volume

492

First Page

27

Last Page

32

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