Strain Modulation of Graphene by Nanoscale Substrate Curvatures: A Molecular View.
Nano Lett
; 18(3): 2098-2104, 2018 03 14.
Article
in En
| MEDLINE
| ID: mdl-29474080
ABSTRACT
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.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Nano Lett
Year:
2018
Document type:
Article