Two-dimensional XC 6 -enes (X = Ge, Sn, Pb) with moderate band gaps, biaxial negative Poisson's ratios, and high carrier mobility
Graphene-based analogs and derivatives provide numerous routes to achieve unconventional properties and potential applications. Particularly, two-dimensional (2D) binary materials of group-IV elements are drawing increasing interest. In this work, we proposed the design of three 2D graphene-based ma...
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Published in | Physical chemistry chemical physics : PCCP Vol. 23; no. 46; pp. 26468 - 26475 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
01.12.2021
|
Online Access | Get full text |
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Summary: | Graphene-based analogs and derivatives provide numerous routes to achieve unconventional properties and potential applications. Particularly, two-dimensional (2D) binary materials of group-IV elements are drawing increasing interest. In this work, we proposed the design of three 2D graphene-based materials, namely, XC
6
-enes (X = Ge, Sn, or Pb), based on first-principles calculations. These new materials possess intriguing properties superior to graphene, such as biaxial negative Poisson's ratio (NPR), moderate bandgap, and high carrier mobility. These XC
6
-enes comprise sp
2
carbon and sp
3
X (X = Ge, Sn, Pb) atoms with hexagonal and pentagonal units by doping graphene with X atoms. The stability and plausibility of these 2D materials are verified from formation energies, phonon spectra,
ab initio
molecular dynamic simulations, and elastic constants. The incorporation of X atoms leads to highly anisotropic mechanical properties along with NPR due to the unique tetrahedral structure and hat-shaped configuration. In the equilibrium state, all the XC
6
-enes are moderate-band-gap semiconductors. The carrier mobilities of the XC
6
-enes were highly anisotropic (∼10
4
cm
−2
V
−1
s
−1
along the [010]-direction). Such outstanding properties make the 2D frameworks promising for application in novel electronic and micromechanical devices. |
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ISSN: | 1463-9076 1463-9084 |
DOI: | 10.1039/D1CP04174F |