Superior Adhesion of Monolayer Amorphous Carbon to Copper.

Zhang, Hongji; Grebenko, Artem K; Iakoubovskii, Konstantin V; Zhang, Hanning; Yamaletdinov, Ruslan; Makarova, Anna; Fedorov, Alexander; Sk, Rejaul et al. · Adv Mater · 2025

basic_science · Level V

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Abstract

The single-atom thickness of graphene holds great potential for device scaling, but its effectiveness as a thin metal-ion diffusion barrier in microelectronics and a corrosion barrier for plasmonic devices is compromised by weak van der Waals interactions with copper (Cu), leading to delamination issues. In contrast, monolayer amorphous carbon (MAC), a recently reported single-atom-thick carbon film with a disordered sp<sup>2</sup> hybridized structure, demonstrates superior adhesion properties. This study reveals that MAC exhibits an adhesion energy of 85 J m<sup>-2</sup> on Cu, which is 13 times greater than that of graphene. This exceptional adhesion is attributed to the formation of covalent-like Cu─C bonds while preserving its sp<sup>2</sup> structure, as evidenced by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Density functional theory (DFT) calculations further elucidate that the corrugated structure of MAC facilitates the hybridization of C 2p<sub>z</sub> orbitals with Cu 4s and 3dz<sup>2</sup> orbitals, promoting strong bonding. These insights indicate that the amorphous structure of MAC significantly enhances adhesion while preserving its elemental composition, providing a pathway to improve the mechanical reliability and performance of two-dimensional (2D) materials on metal substrates in various technological applications.