Laser-assisted graphene layer exfoliation from graphite slab

ABSTRACT

Synthesis of graphene with reduced use of chemical reagents is essential for manufacturing scale-up and to control its structure and properties. In this paper, we report the mechanism for exfoliating graphene from graphite slabs using laser impulse. We set up a molecular dynamics model that accounts for the charge-mediated inter-atomic potential along with the forces from electromagnetic fields of a laser pulse. The role of different laser fluences on the exfoliation process of graphene quantified in terms of the interlayer energy transition, inter-layer displacement jump, and thermal shock propagation in graphene-graphite system. The simulation results confirm the exfoliation of a single layer graphene sheet for the laser power ranging from $100\times {10}^{-14}$ to $2000\times {10}^{-14}$ J/nm². With an increase of laser fluence from $2000\times {10}^{-14}$ to $4000\times {10}^{-14}$ J/nm², there is an increase in the graphene yield via the layer-after-layer exfoliation. The bridging bond dynamics between the successive graphene layers govern the exfoliation of the second layer. The results indicate promises for producing chemical-free graphene on a large scale for industrial applications.

KEYWORDS:

• Laser exfoliation
• graphene
• molecular dynamics
• force field

Acknowledgments

DRM, BJ, RV thankfully acknowledge financial support from the Aeronautics Research & Development Board through the project ACECOST-Phase III at the Indian Institute of Science. DRM thankfully acknowledges DRDO Chair Professorship at the Indian Institute of Science during finalising this paper. BJ also acknowledges financial support as Mari Curie Visiting Researcher at Bauhaus University, Germany through the project Multiscale Fracture.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported by International Research Staff Exchange Scheme (IRSES), FP7-PEOPLE-2010-IRSES, through the project ‘MultiFrac’; Aeronautical Research and Development Board (ARDB) through project ACECOST Phase-III; Defence Research and Development Organization (DRDO) Chair at IISc.