A Curved Graphene Nanoribbon with Multi-Edge Structure and High Intrinsic Charge Carrier Mobility

Abstract

Structurally well-defined graphene nanoribbons (GNRs) have emerged as highly promising materials for the next-generation nanoelectronics. The electronic properties of GNRs critically depend on their edge topologies. Here, we demonstrate the efficient synthesis of a curved GNR (<b>cGNR</b>) with a combined cove, zigzag, and armchair edge structure, through bottom-up synthesis. The curvature of the <b>cGNR</b> is elucidated by the corresponding model compounds tetrabenzo[<i>a,cd,j,lm</i>]perylene (<b>1</b>) and diphenanthrene-fused tetrabenzo[<i>a,cd,j,lm</i>]perylene (<b>2</b>), the structures of which are unambiguously confirmed by the X-ray single-crystal analysis. The resultant multi-edged <b>cGNR</b> exhibits a well-resolved absorption at the near-infrared (NIR) region with a maximum peak at 850 nm, corresponding to a narrow optical energy gap of ∼1.22 eV. Employing THz spectroscopy, we disclose a long scattering time of ∼60 fs, corresponding to a record intrinsic charge carrier mobility of ∼600 cm² V^-1 s^-1 for photogenerated charge carriers in <b>cGNR</b>.