Signatures of paracrystallinity in amorphous silicon

Fuente: arXiv
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Autori principali: Rosset, Louise A. M., Drabold, David A., Deringer, Volker L.
Natura: Preprint
Pubblicazione: 2024
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author Rosset, Louise A. M.
Drabold, David A.
Deringer, Volker L.
author_facet Rosset, Louise A. M.
Drabold, David A.
Deringer, Volker L.
contents The structure of amorphous silicon (a-Si) has been studied for decades. The two main theories are based on a continuous random network and on a `paracrystalline' model, respectively -- the latter being defined as showing localized structural order resembling the crystalline state whilst retaining an overall amorphous network. However, the extent of this local order has been unclear, and experimental data have led to conflicting interpretations. Here we show that signatures of paracrystallinity in an otherwise disordered network are indeed compatible with the existing body of experimental observations for a-Si. We use quantum-mechanically accurate, machine-learning-driven simulations to systematically sample the configurational space of quenched a-Si, thereby allowing us to elucidate the boundary between amorphization and crystallization. We analyze our dataset using structural and local-energy descriptors to show that paracrystalline models are consistent with experiments in both regards. Our work provides a unified explanation for seemingly conflicting theories in one of the most widely studied amorphous networks.
format Preprint
id arxiv_https___arxiv_org_abs_2407_16681
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Signatures of paracrystallinity in amorphous silicon
Rosset, Louise A. M.
Drabold, David A.
Deringer, Volker L.
Materials Science
Disordered Systems and Neural Networks
The structure of amorphous silicon (a-Si) has been studied for decades. The two main theories are based on a continuous random network and on a `paracrystalline' model, respectively -- the latter being defined as showing localized structural order resembling the crystalline state whilst retaining an overall amorphous network. However, the extent of this local order has been unclear, and experimental data have led to conflicting interpretations. Here we show that signatures of paracrystallinity in an otherwise disordered network are indeed compatible with the existing body of experimental observations for a-Si. We use quantum-mechanically accurate, machine-learning-driven simulations to systematically sample the configurational space of quenched a-Si, thereby allowing us to elucidate the boundary between amorphization and crystallization. We analyze our dataset using structural and local-energy descriptors to show that paracrystalline models are consistent with experiments in both regards. Our work provides a unified explanation for seemingly conflicting theories in one of the most widely studied amorphous networks.
title Signatures of paracrystallinity in amorphous silicon
topic Materials Science
Disordered Systems and Neural Networks
url https://arxiv.org/abs/2407.16681