Insights on Defect-Mediated Heterogeneous Nucleation of Graphene on Copper

Ghosh, Priyadarshini and Kumar, Shishir and Ramalingam, Gopalakrishnan and Kochat, Vidya and Radhakrishnan, Madhavan and Dhar, Sukanya and Suwas, Satyam and Ghosh, Arindam and Ravishankar, N and Raghavan, Srinivasan (2015) Insights on Defect-Mediated Heterogeneous Nucleation of Graphene on Copper. In: JOURNAL OF PHYSICAL CHEMISTRY C, 119 (5). pp. 2513-2522.

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Abstract

The grain size of monolayer large area graphene is key to its performance. Microstructural design for the desired grain size requires a fundamental understanding of graphene nucleation and growth. The two levers that can be used to control these aspects are the defect density, whose population can be controlled by annealing, and the gas-phase supersaturation for activation of nucleation at the defect sites. We observe that defects on copper surface, namely dislocations, grain boundaries, triple points, and rolling marks, initiate nucleation of graphene. We show that among these defects dislocations are the most potent nucleation sites, as they get activated at lowest supersaturation. As an illustration, we tailor the defect density and supersaturation to change the domain size of graphene from <1 mu m(2) to >100 mu m(2). Growth data reported in the literature has been summarized on a supersaturation plot, and a regime for defect-dominated growth has been identified. In this growth regime, we demonstrate the spatial control over nucleation at intentionally introduced defects, paving the way for patterned growth of graphene. Our results provide a unified framework for understanding the role of defects in graphene nucleation and can be used as a guideline for controlled growth of graphene.

Item Type:	Journal Article
Publication:	JOURNAL OF PHYSICAL CHEMISTRY C
Additional Information:	Copy right for this article belongs to the AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Physical & Mathematical Sciences > Physics
Date Deposited:	23 Mar 2015 09:57
Last Modified:	23 Mar 2015 09:57
URI:	http://eprints.iisc.ac.in/id/eprint/51082

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