Prediction of a Kinetic Pathway for Fabricating the Narrowest Zigzag Graphene Nanoribbons on Cu(111)

Abstract

The narrowest zigzag graphene nanoribbons (nZGNRs) consisting of linearly fused benzene rings have distinctly superior electronic and spintronic properties; yet, to date, fabrication of nZGNRs via bottom-up self-assembly remains a daunting challenge. Here, based on first-principles calculations, we propose a kinetic pathway for growing nZGNRs on Cu(111) using 1,4dibromo-2,5-bis(bromomethyl)benzene precursors. We show that such a precursor molecule can readily adsorb on Cu(111), accompanied by easy detachment of the four Br substituents. As building blocks for the formation of the nZGNRs, the resulting C 8 H 6 radicals have high diffusional and rotational mobilities on the substrate. Two such radicals can fuse into an nZGNR-like dimer via covalent bond formation by overcoming a kinetic barrier of ∼1.00 eV, with the unsaturated C atoms properly located to allow additional C 8 H 6 radicals to join and elongate the nZGNR. We further examine possible competing byproducts and find that the yields of nZGNRs can be enhanced with proper choices of the substrates. As a comparative study, the precursor molecule of 1,4-bis(bromomethyl)benzene has also been investigated and found to be less desirable in forming the nZGNRs. These findings provide a highly appealing route toward the fabrication of nZGNRs for potential applications in nanoelectronics and spintronics.

Electronic, transport, magnetic, and optical properties of graphene nanoribbons and their optical sensing applications: A comprehensive review

“…[ 190 ] Recently, Yang et al reported the fabrication of the narrowest ZGNRs on Cu(111). [ 191 ] Chen et al reported the fabrication of sub‐10‐nm wide smooth close‐ or open‐edged graphene nanoribbons by squashing the CNTs under high pressure and sufficient temperature conditions. [ 192 ] Moreover, using regioselective Scholl reaction, Yao et al synthesized the nonplanar graphene nanoribbons with fjord edges.…”