Details
| Original language | English |
|---|---|
| Article number | 054105 |
| Number of pages | 12 |
| Journal | Physical Review B |
| Volume | 99 |
| Issue number | 5 |
| Publication status | Published - 21 Feb 2019 |
Abstract
Flexoelectricity is a form of electromechanical coupling that has recently emerged because, unlike piezoelectricity, it is theoretically possible in any dielectric material. Two-dimensional (2D) materials have also garnered significant interest because of their unusual electromechanical properties and high flexibility, but the intrinsic flexoelectric properties of these materials remain unresolved. In this work, using atomistic modeling accounting for charge-dipole interactions, we report the intrinsic flexoelectric constants for a range of two-dimensional materials, including graphene allotropes, nitrides, graphene analogs of group-IV elements, and the transition metal dichalcogenides (TMDCs). We accomplish this through a proposed mechanical bending scheme that eliminates the piezoelectric contribution to the total polarization, which enables us to directly measure the flexoelectric constants. While flat 2D materials like graphene have low flexoelectric constants due to weak π-σ interactions, buckling is found to increase the flexoelectric constants in monolayer group-IV elements. Finally, due to significantly enhanced charge transfer coupled with structural asymmetry due to bending, the TMDCs are found to have the largest flexoelectric constants, including MoS2 having a flexoelectric constant ten times larger than graphene.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Physical Review B, Vol. 99, No. 5, 054105, 21.02.2019.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Intrinsic bending flexoelectric constants in two-dimensional materials
AU - Zhuang, Xiaoying
AU - He, Bo
AU - Javvaji, Brahmanandam
AU - Park, Harold S.
N1 - Funding information: The authors would like to acknowledge the support of NSFC (11772234), the Fundamental Research Funds for the Central Universities and ERC Starting Grant (802205, X.Z.).
PY - 2019/2/21
Y1 - 2019/2/21
N2 - Flexoelectricity is a form of electromechanical coupling that has recently emerged because, unlike piezoelectricity, it is theoretically possible in any dielectric material. Two-dimensional (2D) materials have also garnered significant interest because of their unusual electromechanical properties and high flexibility, but the intrinsic flexoelectric properties of these materials remain unresolved. In this work, using atomistic modeling accounting for charge-dipole interactions, we report the intrinsic flexoelectric constants for a range of two-dimensional materials, including graphene allotropes, nitrides, graphene analogs of group-IV elements, and the transition metal dichalcogenides (TMDCs). We accomplish this through a proposed mechanical bending scheme that eliminates the piezoelectric contribution to the total polarization, which enables us to directly measure the flexoelectric constants. While flat 2D materials like graphene have low flexoelectric constants due to weak π-σ interactions, buckling is found to increase the flexoelectric constants in monolayer group-IV elements. Finally, due to significantly enhanced charge transfer coupled with structural asymmetry due to bending, the TMDCs are found to have the largest flexoelectric constants, including MoS2 having a flexoelectric constant ten times larger than graphene.
AB - Flexoelectricity is a form of electromechanical coupling that has recently emerged because, unlike piezoelectricity, it is theoretically possible in any dielectric material. Two-dimensional (2D) materials have also garnered significant interest because of their unusual electromechanical properties and high flexibility, but the intrinsic flexoelectric properties of these materials remain unresolved. In this work, using atomistic modeling accounting for charge-dipole interactions, we report the intrinsic flexoelectric constants for a range of two-dimensional materials, including graphene allotropes, nitrides, graphene analogs of group-IV elements, and the transition metal dichalcogenides (TMDCs). We accomplish this through a proposed mechanical bending scheme that eliminates the piezoelectric contribution to the total polarization, which enables us to directly measure the flexoelectric constants. While flat 2D materials like graphene have low flexoelectric constants due to weak π-σ interactions, buckling is found to increase the flexoelectric constants in monolayer group-IV elements. Finally, due to significantly enhanced charge transfer coupled with structural asymmetry due to bending, the TMDCs are found to have the largest flexoelectric constants, including MoS2 having a flexoelectric constant ten times larger than graphene.
UR - http://www.scopus.com/inward/record.url?scp=85062559439&partnerID=8YFLogxK
U2 - 10.48550/arXiv.2208.09644
DO - 10.48550/arXiv.2208.09644
M3 - Article
AN - SCOPUS:85062559439
VL - 99
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 5
M1 - 054105
ER -