A nanoindenter was used to compress individual particles of hydrogenated amorphous silicon (a-Si:H) ranging in diameter from 290 nm to 780 nm. The colloidal synthesis used to produce the particles enables the hydrogen content to be manipulated over a wide range, from about 5 at. % to 50 at. %, making these a-Si:H particles promising for applications in lithium ion batteries, hydrogen storage, and optical metamaterials. Force-displacement curves generated using a tungsten probe flattened with focused ion beam exhibited elastic and then plastic deformations, followed by fracture and crushing of the particles. For particles with 5% and 50% H, Young's moduli, yield strengths, and compressive strengths were 73.5(±19.5) GPa, 5.8 GPa, and 3.2(±0.1)-9.3(±0.6) GPa and 31.2(±9.0) GPa, 2.5 GPa, and 1.8 (±0.3)-5.3(±0.8) GPa, respectively. Particles with more hydrogen were significantly more compliant and weaker. This is consistent with atomistically detailed molecular dynamics simulations, which revealed compression forms of an interphase of H atom clusters that weakens the material.
T. Jiang et al., "Mechanical Properties of Hydrogenated Amorphous Silicon (A-Si:H) Particles," Journal of Applied Physics, vol. 126, American Institute of Physics (AIP), Nov 2019.
The definitive version is available at https://doi.org/10.1063/1.5117282
Civil, Architectural and Environmental Engineering
Center for Research in Energy and Environment (CREE)
Keywords and Phrases
Compressive strength; Elastic moduli; Hydrogen storage; Hydrogenation; Ion beams; Lithium-ion batteries; Molecular dynamics; Optical materials, Colloidal synthesis; Compression forms; Force-displacement curves; Hydrogen contents; Hydrogenated amorphous silicon (a-Si:H); Individual particles; Molecular dynamics simulations; Optical metamaterials, Amorphous silicon
International Standard Serial Number (ISSN)
Article - Journal
© 2019 The Authors, All rights reserved.
01 Nov 2019