Abstract

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.

Department(s)

Civil, Architectural and Environmental Engineering

Comments

The authors acknowledge funding of this work by the Robert A. Welch Foundation (Grant No. F-1464) and the Center for Dynamics and Control of Materials (CDCM) supported by the National Science Foundation (NSF) under NSF Award No. DMR-1720595.

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)

0021-8979; 1089-7550

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2019 The Authors, All rights reserved.

Publication Date

01 Nov 2019

Share

 
COinS