Confined CVD Synthesis and Temperature‐Dependent Spectroscopic Properties of Bilayer Graphene Ribbon Arrays with Bifunctional Modulation of Adhesion Metal

Abstract Bilayer graphene ribbons (GRs) hold great promise for the fabrication of next‐generation nanodevices, thanks to unparalleled electronic properties, especially the tunable bandgap in association with twist angle, ribbon width, edge structure, and interlayer coupling. A common challenge in manufacturing bilayer GRs via templated chemical vapor deposition (CVD) approach is uncontrollable dewetting of micro‐ and nano‐scaled patterned metal substrates. Herein, a confined CVD synthetic strategy of bilayer GR arrays is proposed, by utilizing the bifunctional Ni as a buffered adhesion layer to regulate the anisotropic dewetting of metal film in the V‐groove and as a carbon‐dissolution regulated metal to initiate the bilayer nucleation. Using C 2 H 4 as direct donor of C dimer species, high‐quality bilayer GR arrays are synthesized on regular CuNi ribbons with twist angles at 900 °C, harnessing the non‐equilibrium jointly induced by confined V‐groove and C dimer species. The nucleation and growth mechanism of bilayer GR are investigated with density functional theory (DFT) calculations. The as‐grown bilayer GRs display distinctive variable temperature Raman and photoluminescence properties. Our results contribute to a highly controllable technique for fabricating twisted bilayer GR arrays and deep insights into the optical properties of bilayer GRs for potential optoelectronics applications.