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

TLDR

Monolayer transition metal dichalcogenides yield high‑quality electronic materials, but their exfoliated size is typically limited to micrometers. The authors aimed to extend monolayer size by depositing atomically flat gold layers on polymer supports. The strong van der Waals adhesion of the gold layer enabled centimeter‑scale exfoliation of the monolayers. They reassembled the multilayers into artificial lattices, such as a MoSe₂/WSe₂ single‑crystal bilayer with a twist angle that quenches intralayer exciton formation. Liu et al., Science, this issue p.

Abstract

Larger monolayers with gold tapes Although the exfoliation of monolayers of materials such as transition metal dichalcogenides produces high-quality electronic materials with low defect densities, the size of the monolayers is limited to the micrometer scale. Liu et al. modified this method by creating atomically flat gold layers on polymer supports. The strong van der Waals adhesion of the gold layer allowed monolayers to be exfoliated on the centimeter scale. Multilayers could be reassembled to artificial structures, such as a MoSe 2 /WSe 2 single-crystal bilayer with a twist angle chosen to quench intralayer exciton formation. Science , this issue p. 903