Strength of defective graphene – atomistic modeling and experiments
Catalin Picu (Rensselaer Polytechnic Institu), Ardavan Zandiatashbar (), Nikhil Koratkar (), Gwan Hyoung Lee (), James Hone ()
From Atomistics to Reality: Spanning Scales in Simulations and Experiments Symposium B
Tue 2:40 - 4:00
CIT 227
Mono-layer graphene is known to have interesting properties, which are quite different from those of multi-layer graphene and of graphite. However, most applications make use of defective and oxidized graphene. In this work we develop a method allowing the estimation of the strength and moduli of defective graphene based on its Raman spectrum. This is based on testing mono-layers of graphene with controlled defect density and on modeling and simulation of the deformation of such structures. Defects are introduced by exposure to oxygen plasma and their density is evaluated using Raman and Auger spectroscopy. The mechanical properties are determined by indentation of suspended graphene sheets with an AFM tip. Atomistic models are used to determine the nature of defects and their evolution during exposure to plasma, and to evaluate the strength and moduli of sheets with various concentrations of defects. The comparison of experimental and simulation data is favorable and provides confidence in the insight gained on this physics. The results allow relating strength to Raman spectra, which therefore becomes a non-destructive testing method for these materials.