Motivated by progress in the mechanochemical synthesis of alkynyl carbon materials, we propose two-dimensional carbon materials (QC-graphyne, P-graphyne, and D-graphyne) that are accessible to bottom-up synthesis using P-quinodimethane, pyren, coronene, and dibenzo[bc,kl]coronene as molecular precursors. First-principles calculations demonstrate high stability in comparison to experimentally existing two-dimensional alkynyl carbon materials (naphyne, γ-graphyne, graphdiyne, and graphtetrayne). Importantly, QC-graphyne, P-graphyne, and D-graphyne turn out to be semimetals with distorted type I Dirac cones. Their direction-dependent high Fermi velocities in excess of 105 m/s can compete with those of most known carbon Dirac materials. A Slater–Koster tight-binding model is adopted to verify the formation of a π-conjugated framework due to coupling between carbon pz orbitals. The Dirac cones survive under uniaxial and biaxial in-plane strain with only minor modifications.
Bibliographical noteKAUST Repository Item: Exported on 2021-11-24
Acknowledgements: The authors acknowledge generous financial support from the National Natural Science Foundation of China (nos. 61974116 and 61804120), China Postdoctoral Science Foundation (nos. 2019TQ0243 and 2019M663646), and Key Scientific Research Project of the Education Department of the Shannxi-Key Laboratory Project (no. 20JS066). The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). The authors thank Xidian University for computational resources and support.
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- General Energy
- Physical and Theoretical Chemistry
- Electronic, Optical and Magnetic Materials