Sensitivity to strains and defects for manipulating the conductivity of graphene

Abstract

Implementing the quantum-mechanical Kubo-Greenwood formalism for the numerical calculation of dc conductivity, we demonstrate that the electron transport properties of a graphene layer can be tailored through the combined effect of defects (point and line scatterers) and strains (uniaxial tension and shear), which are commonly present in a graphene sample due to the features of its growth procedure and when the sample is used in devices. Motivated by two experimental works (He X. et al. Appl. Phys. Lett., 104 (2014) 243108; 105 (2014) 083108), where authors did not observe the transport gap even at large (22.5% of tensile and 16.7% of shear) deformations, we explain possible reasons, emphasizing on graphene's strain and defect sensing. The strain- and defect-induced electron-hole asymmetry and anisotropy of conductivity, and its nonmonotony as a function of deformation suggest perspectives for the strain-defect engineering of electrotransport properties of graphene and related 2D materials.

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“…for instance, introduction of thin co 2 MnSi layer lead to decrease of transition temperature to 400 °c [54]. ru seed layer is the other option for using fePd in MtJs [55]. the other way is introduction of diffusion barrier layers.…”

“…Under the emerging stresses, migration of existing dislocations is activated and new dislocations are generated [54]. these processes can accelerate both self-diffusion [55,56] and heterogeneous diffusion of interstitial atoms [57,58] and substitutional atoms [59]. In addition, due to this type of heat treatment, the concentration of point defects that significantly exceeds the equilibrium is retained.…”

“…the method of processing (treatment) of the contact surfaces and their state [54,55] may strongly affect the transient resistance. Nowadays, it is proved by the scientists of different countries that the application of electron beam processing (EBP) enables to obtain a mirrorsmooth surface of the materials [56], nanostructurize [57] and homogenize the material [58].…”

“…the microstructure is refined, the mechanical properties are improved (the strength properties are increased), which can be further regulated using various regimes of the heat treatment [48,49]. this concerns not only aluminium alloys, but also a wide spectrum of both three-dimensional [50-54] and two-dimensional [55][56][57][58] materials.…”

Influence of Defect Number, Distribution Continuity and Orientation on Tensile Strengths of the CNT-Based Networks: A Molecular Dynamics Study

“…Nevertheless, defects are reported to bring benefits in tailoring the properties of CNT/graphene and obtaining new functionality in recent years. Defects can be controlled to modify the transport properties and catalytic activity of the grapheme [ 13 , 14 ], optimize the electrical performance of the graphene-based nano-devices [ 15 ], and obtain graphene clusters with electro-catalytic capability for better efficiency of the fuel cells [ 16 ]. The defect engineering of CNT or graphene has been proposed to achieve the material design and obtain different functionalities via the control of defects [ 9 , 17 ].…”