Designing All Graphdiyne Materials as Graphene Derivatives: Topologically Driven Modulation of Electronic Properties

Abstract

Designing new 2D systems with tunable properties is an important subject for science and technology. Starting from graphene, we developed an algorithm to systematically generate 2D carbon crystals belonging to the family of graphdiynes (GDYs) and having different structures and sp/sp 2 carbon ratios. We analyze how structural and topological effects can tune the relative stability and the electronic behavior, to propose a rationale for the development of new systems with tailored properties. A total of 26 structures have been generated, including the already known polymorphs such as α-, β-, and γ-GDY. Periodic density functional theory calculations have been employed to optimize the 2D crystal structures and to compute the total energy, the band structure, and the density of states. Relative energies with respect to graphene have been found to increase when the values of the carbon sp/sp 2 ratio increase, following however different trends based on the peculiar topologies present in the crystals. These topologies also influence the band structure, giving rise to semiconductors with a finite band gap, zero-gap semiconductors displaying Dirac cones, or metallic systems. The different trends allow identifying some topological effects as possible guidelines in the design of new 2D carbon materials beyond graphene.

Density functional theory and ab‐initio molecular dynamics calculations on the opto‐electronic, spintronic, and energies of pure and TiO x doped monatomic γ‐graphyne

“…Spin up (solid black lines) and spin down band (dotted red lines) diagrams for both these systems were drawn and are displayed in Figure 6C,D, respectively. Our calculated band structure of intrinsic γ‐graphyne carries a band gap of ~0.5 eV along with appearance of Dirac cone at M‐point as shown in Figure 6A, which agrees well with earlier reports, 64,83‐85 thus validating our calculations and obtained results through these techniques.…”

2D graphdiyne: an emerging carbon material

“…The sp-hybridized carbon-carbon triple bond (-CRC-) with many fascinating properties (e.g., no cis-trans isomers, linear structure, the high conjugation, etc. ), 10,11 especially its inhomogeneity of distribution of surface charges, can trigger peculiar properties that transitional carbon materials do not possess. As a result, scientists have long been laying out the synthesis of highly sp-hybridized new carbon allotropes with transformative properties.…”

Performance Enhancement and Comparison of Graphene Field Effect Transistor Devices Coated with HMDS Layer

“…Graphene [1][2][3][4][5][6][7] is a rapidly growing two-dimensional one atom thick carbon material with great potential in linear dispersion [1,2]. Presently, graphene-based electronic devices [3] are known for attractive peculiarities, like the quantum hall effect [4], tunneling effect [5], and many other transport properties as well as electronic properties [6,7], mechanical properties [8], and optical properties [9,10] owing to their carrier density and polarity, as well as high charge mobility for both electrons and holes. The electronic properties of graphene make it one of the promising materials in generating high-speed sensor devices [11][12][13].…”