Disassembling 2D van der Waals crystals into macroscopic monolayers and reassembling into artificial lattices

Abstract

Two-dimensional materials from layered van der Waals (vdW) crystals hold great promise for electronic, optoelectronic, and quantum devices, but technological implementation will be hampered by the lack of high-throughput techniques for exfoliating single-crystal monolayers with sufficient size and high quality. Here, we report a facile method to disassemble vdW single crystals layer by layer into monolayers with near-unity yield and with dimensions limited only by bulk crystal sizes. The macroscopic monolayers are comparable in quality to microscopic monolayers from conventional Scotch tape exfoliation. The monolayers can be assembled into macroscopic artificial structures, including transition metal dichalcogenide multilayers with broken inversion symmetry and substantially enhanced nonlinear optical response. This approach takes us one step closer to mass production of macroscopic monolayers and bulk-like artificial materials with controllable properties.

Strain and Charge Doping Fingerprints of the Strong Interaction between Monolayer MoS2 and Gold

“…Gold-mediated exfoliation has quickly attracted attention and has been utilized in the fabrication of flexible gas sensors, 4 lithography patterning for transistor applications, 5 and construction of large-area van der Waals (vdW) heterostructures. 6 , 7 …”

2D Materials and Heterostructures at Extreme Pressure

“…On the other hand, when heterostructures consist of layered materials with a twist or a lattice mismatch, nanoscale Moiré patterns usually emerge due to weak vdW interactions (Figure 11e-g). [248][249][250][251][252] These Moiré patterns manipulate heterostructures' electronic and optoelectronic properties and result in multiple interesting phenomena, opening up a new direction of nano-optoelectronics/electronics. [248,249,[253][254][255][256] As an example, the physics of Moiré patterns in h-BN/graphene heterostructures has been investigated, demonstrating that the periodic potential result in the formation of new Dirac cones, bandgap opening, and the emergence of Hofstadter butterfly states (Figure 11g).…”

Bioelectronics‐Related 2D Materials Beyond Graphene: Fundamentals, Properties, and Applications

“…For example, millimetersize monolayers have been successfully prepared by Au-assisted exfoliation, which was attributed to the strong interaction between Au and layered crystals. [151,152,155,156] As a typical bottom-up method, CVD is well suited for the fabrication of large-area 2D materials with a controlled number of layers. The synthesis of different kinds of 2D materials requires a careful selection of chalcogen/metal sources and substrates (SiO 2 /Si, sapphire, or mica) according to source vapor pressure and the growth conditions of target products.…”

“…For example, millimeter‐size monolayers have been successfully prepared by Au‐assisted exfoliation, which was attributed to the strong interaction between Au and layered crystals. [ 151,152,155,156 ]…”