Cp-Graphyne: A Low-Energy Graphyne Polymorph with Double Distorted Dirac Points

Abstract

In the present investigation, we have proposed a novel form of two-dimensional (2D) carbon allotropes with the aid of first-principle density functional theory-based calculations. The carbon polymorph is mainly composed of carbon pentagons (cp) and acetylenic linkers and hence named cp-graphyne. This 2D material is energetically more preferable than the rest of the semimetals of graphyne family, including graphdiyne monolayer. Close inspection of lattice dynamics and thermal and mechanical properties demonstrates the excellent dynamic, thermal, and mechanical stabilities of cp-graphyne. Interestingly, cp-graphyne exhibits a semimetallic nature and possesses double distorted Dirac points in the electronic band spectrum. The Fermi velocities ( v f ) of cp-graphyne are highly anisotropic and are predicted to be in the range of 1.50–8.20 × 10 5 m/s. Furthermore, the analysis of structural and electronic properties of the cp-graphyne bilayer discloses the presence of self-doped Dirac-like points nearer to the Fermi level in the electronic spectrum.

Detection of odor quality and ripening stage of Mangifera indica L. by graphdiyne nanosheet - a DFT outlook

“…Moreover, GGA-PBE exchange-correlation functional is an optimum choice for studying the interaction behavior of different volatiles on Gdn-NS. In addition, −7.142 eV/atom is recorded based on QMC calculation, which is also validated with the proposed work (−7.20 eV/atom) [50]. Nevertheless, the E coh of Gdn-NS in this work is somewhat smaller than graphene nanosheet (7.464 eV) [49].…”

New nanoporous graphyne monolayer as nodal line semimetal: Double Dirac points with an ultrahigh Fermi velocity

“…Although many 2D carbon allotropes have been predicted, combining structural properties of the above two classes have been scarce up to now. [20][21][22] The topologically nontrivial materials, such as topological semimetals, have attracted broad interest.…”

Palgraphyne: A Promising 2D Carbon Dirac Semimetal with Strong Mechanical and Electronic Anisotropy

“…The first one is the plane graphene‐like allotropes (e.g., phagraphene, H‐net, biphenylene carbon, and “QPHT” graphene composed of quadrangular, pentagonal, and hexagonal rings and large tetradecagonal pores), in which all of the atoms are sp 2 hybridized. The second type is the plane graphyne‐like phases (e.g., δ‐,, α‐, β‐graphyne, 6,6,12‐graphyne, and cp‐graphyne), in which there are sp‐hybridized C—C atomic linkages in addition to sp 2 ‐hybridized C atoms. The third one is multilayer quasi‐2D systems (e.g., penta‐graphene and ph‐graphene), which have both four‐coordinated C atoms with sp 3 hybridization and sp 2 ‐bonded C atoms.…”

“…In addition to the hexagonal lattice, there are also some novel Dirac semimetals with nonhexagon symmetry. For example, the Dirac cones of 6,6,12‐graphyne, octagon and pentagon graphene‐zigzag (OPG‐Z) (Pmam), phagraphene (Pmg), and cp‐graphyne (P4/mbm) are related to their rectangular symmetry rather than hexagonal symmetry. As a matter of fact, the condition of forming the Dirac state is very rigorous.…”

“…As has been confirmed, due to the linear Dirac state, 2D carbon Dirac semimetals [13,[40][41][42][46][47][48] can exhibit interesting physical properties, such as ballistic charge transport, high carrier mobility, and nontrivial topological properties, [49][50][51] providing promising applications for next-generation electronic nanodevices. Moreover, the strong anisotropy of Dirac Fermion transport is highly desirable for the development of carbon-based nanodevices for precision measuring and sensing.…”