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 SiO2nanospheres 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.
Strain Modulation of Graphene by Nanoscale Substrate Curvatures : A Molecular View / Y. Zhang, M. Heiranian, B. Janicek, Z. Budrikis, S. Zapperi, P.Y. Huang, H.T. Johnson, N.R. Aluru, J.W. Lyding, N. Mason. - In: NANO LETTERS. - ISSN 1530-6984. - 18:3(2018 Mar 14), pp. 2098-2104.
|Titolo:||Strain Modulation of Graphene by Nanoscale Substrate Curvatures : A Molecular View|
|Parole Chiave:||2D material; deformation; graphene; nanoparticles; pseudomagnetic field; strain|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Progetto:||Size effects in fracture and plasticity|
|Data di pubblicazione:||14-mar-2018|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/acs.nanolett.8b00273|
|Appare nelle tipologie:||01 - Articolo su periodico|