Thermal and electronic transport characteristics of highly stretchable graphene kirigami

Abstract

For centuries, cutting and folding papers with special patterns have been used to build beautiful, flexible and complex three-dimensional structures. Inspired by the old idea of kirigami (paper cutting), and the outstanding properties of graphene, recently graphene kirigami structures were fabricated to enhance the stretchability of graphene. However, the possibility of further tuning the electronic and thermal transport along the 2D kirigami structures has remained original to investigate. We therefore performed extensive atomistic simulations to explore the electronic, heat and load transfer along various graphene kirigami structures. The mechanical response and thermal transport were explored using classical molecular dynamics simulations. We then used a real-space Kubo-Greenwood formalism to investigate the charge transport characteristics in graphene kirigami. Our results reveal that graphene kirigami structures present highly anisotropic thermal and electrical transport. Interestingly, we show the possibility of tuning the thermal conductivity of graphene by four orders of magnitude. Moreover, we discuss the engineering of kirigami patterns to further enhance their stretchability by more than 10 times as compared with pristine graphene. Our study not only provides a general understanding concerning the engineering of electronic, thermal and mechanical response of graphene, but more importantly can also be useful to guide future studies with respect to the synthesis of other 2D material kirigami structures, to reach highly flexible and stretchable nanostructures with finely tunable electronic and thermal properties.

Nanoporous graphene: A 2D semiconductor with anisotropic mechanical, optical and thermal conduction properties

“…Exhibiting linear elasticity reveals that NPG behaves analogous to densely packed and defect-free 2D materials, like; graphene, MoS 2 and borophene, in which the deformation is achieved mainly by the bond-elongation. We remind that in the case of graphene kirigami, at the starting points of the stretching the deformation proceeds mostly by the structural deflection rather than the bond-elongation, which can results in an order of magnitude higher stretchability than pristine graphene [52]. Observation of linear elasticity in NPG sheet suggest that its stretchability may not reach high values since the Interestingly, after reaching the ultimate tensile point, for the loading along the zigzag direction the stress values suddenly drop, whereas along the armchair direction the drop in the stress-strain curve happens very smoothly.…”

“…One of the most appealing points of graphene lies in its ability to exhibit vastly tuneable electronic, optical and thermal properties, by mechanical straining [30][31][32][33][34], defect engineering [35][36][37][38][39] or chemical doping [40][41][42][43][44]. In particular, creating various configurations of patterned cuts in graphene using the lithography techniques, such as the graphene kirigami [45], graphene nanomesh [46] or graphene antidot lattices [47,48] and porous graphene [49], have been successfully employed to open a band-gap in graphene [50][51][52], enhance its efficiency for various chemical processes [53][54][55] and prepare it for advanced technologies, like the DNA sequencing [56][57][58]. Nevertheless, the fabrication of porous graphene nanomembranes through the employment of lithography methods requires additional processing steps after the synthesis of pristine graphene, which are not only complicated in practice but also time consuming and expensive as well.…”

Anomalous Thermal Response of Graphene Kirigami Induced by Tailored Shape to Uniaxial Tensile Strain: A Molecular Dynamics Study

“…The mechanical properties of these kirigami structures were investigated. To avoid any nonphysical strain hardening and spurious high bond forces [27,28], the cut-off distance was set to 0.2 nm [29][30][31]. When the system reached the equilibrium state, as the deformation-control method, the tensile loading was applied with a strain rate of 0.0001/ps by scaling all atomic coordinates accordingly for each 1000 steps under the NPT ensemble.…”

Mechanical, optoelectronic and transport properties of single-layer Ca2N and Sr2N electrides

“…The in-depth understanding of 2D electride properties not only plays crucial role for the nanodevices design, but it may also suggest new applications for their usage. Since experimental studies for the evaluation of the properties of 2D materials are complicated, time consuming and expensive, theoretical approaches can be considered as viable alternatives to explore their various properties [19][20][21][22][23][24][25][26][27][28][29]. In the present investigation, we therefore studied the mechanical, electronic and optical properties of singlelayer and free-standing Ca 2 N and Sr 2 N sheet using extensive first-principles density functional theory (DFT) simulations.…”