Strain Modulation of Graphene by Nanoscale Substrate Curvatures: A Molecular View
- University of Illinois at Urbana-Champaign
- Institute for Scientific Interchange Foundation
- Center for Complexity and Biosystems
- University of Milan
Spatially nonuniform strain is important for engineering the pseudomagnetic field and band structure of graphene. Despite the wide interest in strain engineering, there is still a lack of control on device-compatible strain patterns due to the limited understanding of the structure-strain relationship. Here, we study the effect of substrate corrugation and curvature on the strain profiles of graphene via combined experimental and theoretical studies of a model system: graphene on closely packed SiO2 nanospheres with different diameters (20-200 nm). Experimentally, via quantitative Raman analysis, we observe partial adhesion and wrinkle features and find that smaller nanospheres induce larger tensile strain in graphene; theoretically, molecular dynamics simulations confirm the same microscopic structure and size dependence of strain and reveal that a larger strain is caused by a stronger, inhomogeneous interaction force between smaller nanospheres and graphene. This molecular-level understanding of the strain mechanism is important for strain engineering of graphene and other two-dimensional materials.
|Tila||Julkaistu - 14 maaliskuuta 2018|
|OKM-julkaisutyyppi||A1 Julkaistu artikkeli, soviteltu|