Negative and near-zero Poisson's ratios in 2D graphene/MoS2 and graphene/h-BN heterostructures. Issue 12 (26th February 2020)

• Record Type: Journal Article
• Authors: Li, Xiaowen; Huang, Chuanwei; Hu, Songbai; Deng, Bei; Chen, Zuhuang; Han, Wenqiao; Chen, Lang
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 12(2020)
• Page Start: 4021
• Page End: 4029
• Publication Date: 2020-02-26
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9tc06424a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : We report the negative Poisson's ratios (NPR) in vdW heterostructures, sharing distinct crystal structures from all other known NPR materials. Abstract : Negative and near-zero Poisson's ratio materials are mechanical metamaterials that host an improved strain energy absorption property with respect to conventional materials. By using first-principles calculations, we report the negative and near-zero Poisson's ratios in van der Waals (vdW) heterostructures, such as graphene/hexagonal molybdenum disulfide (G/MoS2 ) and graphene/hexagonal boron nitride (G/h-BN), sharing distinct crystal structures from all other known negative and near-zero Poisson's ratio materials. However, the Poisson's ratios of the interfacial layer in bilayer MoS2 and h-BN are positive and near-zero along the out-of-plane direction, respectively, which are quite different from the Poisson's ratios of G/MoS2 and G/h-BN heterostructures. Therefore, these behaviors are unique to vdW heterostructures. We attribute these negative Poisson's ratio behaviors to the special interaction of p z orbitals between the interfacial layers. Furthermore, we observed among them high-order elastic constants in the out-of-plane direction, which exhibit nonlinear stress–strain responses. These results are significant for the preparation of G/h-BN and G/MoS2 heterostructures. The combinations of tunable negative/near-zero Poisson's ratios with the excellent electrical/optical properties of G/MoS2 and G/h-BN heterostructures will pave the way to a wide range of applications in novel auxetic molecular sieves and electrodes.