Three-dimensional Architecture Enabled by Strained Two-dimensional Material Heterojunction

Abstract

Engineering the structure of materials endows them with novel physical properties across a wide range of length scales. With high in-plane stiffness and strength, but low flexural rigidity, two-dimensional (2D) materials are excellent building blocks for nanostructure engineering. They can be easily bent and folded to build three-dimensional (3D) architectures. Taking advantage of the large lattice mismatch between the constituents, we demonstrate a 3D heterogeneous architecture combining a basal BiSe nanoplate and wavelike BiTe edges buckling up and down forming periodic ripples. Unlike 2D heterostructures directly grown on substrates, the solution-based synthesis allows the heterostructures to be free from substrate influence during the formation process. The balance between bending and in-plane strain energies gives rise to controllable rippling of the material. Our experimental results show clear evidence that the wavelengths and amplitudes of the ripples are dependent on both the widths and thicknesses of the rippled material, matching well with continuum mechanics analysis. The rippled BiSe/BiTe heterojunction broadens the horizon for the application of 2D materials heterojunction and the design and fabrication of 3D architectures based on them, which could provide a platform to enable nanoscale structure generation and associated photonic/electronic properties manipulation for optoelectronic and electromechanic applications.

Strain Engineering of 2D Materials: Issues and Opportunities at the Interface

“…As illustrated in Figure a–c, compressive strain to 2D materials can be introduced by directly compressing/prestretching the substrate, applying thermal stress, and growing/transferring 2D materials on the substrate (including 2D materials themselves) with a relatively smaller lattice constant. On a relatively stiff substrate, buckle delamination is typically observed (Figure d–f) . On a relatively compliant substrate, wrinkles are more likely to occur (Figure g–i) .…”

“…f) Tilted‐view SEM image shows three buckles at each edge of the Bi 2 Se 3 /Bi 2 Te 3 heterojunction. Reproduced with permission . Copyright 2018, American Chemical Society.…”

Recent Advances in Strain-Induced Piezoelectric and Piezoresistive Effect-Engineered 2D Semiconductors for Adaptive Electronics and Optoelectronics

“…The strained 2D PbI 2 offers reference for potential optoelectronic device applications. The wrinkles also introduced in massive reduced graphene oxide [ 156 ], WS 2 [ 157 ], and Bi 2 Se 3 /Bi 2 Te 3 heterostructure [ 158 ] by the similar method; as well, the theoretical foundation is getting better and better [ 159 , 160 ].…”

Strain-driven tunable topological states in Bi2Se3

“…Furthermore, recent studies point to the feasibility to induce controllable strain either in thin films or 2D structures. Strained structures of a single material such as Bi 2 Se 3 films [16], layered structures containing two compounds such as Bi 2 Te 3 /Sb 2 Te 3 [31] and Bi 2 Se 3 /In 2 Se [22] or even Bi 2 Se 3 /Bi 2 Te 3 lateral heterojunctions with a large lattice mismatch [32] have been synthesized. In these strained structures either uniform strain or a strain gradient is achieved.…”