https://doi.org/10.1140/epjp/s13360-024-05615-z
Regular Article
First-principles study on the structural and electronic properties of the AB-stacked γ-graphyne bilayer: a new 2D carbon allotrope with tunable bandgap
School of Physics and Information Science, Shaanxi University of Science and Technology, 710021, Xi’an, People’s Republic of China
Received:
30
June
2024
Accepted:
3
September
2024
Published online:
11
September
2024
Vertical stacking of two-dimensional (2D) materials has provided an unprecedented platform to create new hybrid materials and modulate various properties. In this work, the structural and electronic properties of bilayer γ-graphyne have been systematically investigated through first-principles calculations. The AB stacking is confirmed to be more stable than the AA stacking for the γ-graphyne, along with a stacking-dependent electronic bandgap. Besides the usual van der Waals (vdW) homogeneous stacks, a new 2D carbon allotrope can be relaxed from the initial AB-stacked configuration, which is more dynamically stable than the vdW stacks, and possesses a formation energy close to that of a single-layer γ-graphyne. The wrinkled sublayers of the new phase lead to the absence of acetylene linkages in the carbon network, causing dramatic changes in its electronic structure, i.e., the new 2D carbon allotrope exhibits a semiconducting behavior with a large indirect bandgap of 1.506 eV. More interestingly, a conversion from indirect bandgap to direct bandgap, as well as a tunable bandgap ranging from 1.265 to 1.883 eV, can be realized via the in-plane biaxial strain for the new phase. Thus, the results of this work suggest the great potential of bilayer γ-graphyne, and provide a new approach to constructing novel 2D carbon allotropes through vertical stacking of graphyne.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
