Gaussian approximation potential for amorphous Si : H
نویسندگان
چکیده
Hydrogenation of amorphous silicon $(a\text{\ensuremath{-}}\mathrm{Si} : \mathrm{H})$ is critical for reducing defect densities, passivating midgap states and surfaces, improving photoconductivity in silicon-based electro-optical devices. Modeling the atomic-scale structure this material to understanding these processes, which turn needed describe $c\text{\ensuremath{-}}\mathrm{Si}/a\text{\ensuremath{-}}\mathrm{Si} \mathrm{H}$ heterojunctions that are at heart modern solar cells with world-record efficiency. Density functional theory (DFT) studies achieve required high accuracy but limited moderate system sizes 100 atoms or so by their computational cost. Simulations materials have been hindered cost because large structural models capture medium-range order characteristic such materials. Empirical potential much faster, not sufficient correctly frustrated local structure. Data-driven, machine-learned interatomic potentials broken impasse highly successful describing a variety elemental phase. Here, we extend Gaussian approximation (GAP) incorporating interaction hydrogen, thereby significantly degree realism can be modeled. We show our Si H GAP enables simulation hydrogenated an very close DFT expense run times reduced several orders magnitude structures. demonstrate capabilities creating liquid showing energies, forces, stresses excellent agreement results, as captured bond angle distributions both experiments.
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ژورنال
عنوان ژورنال: Physical Review Materials
سال: 2022
ISSN: ['2476-0455', '2475-9953']
DOI: https://doi.org/10.1103/physrevmaterials.6.065603