学术文献库

The unique physics found in moiré superlattices of twisted or lattice-mismatched atomic layers hold great promise for future quantum technologies. However, twisted configurations are typically thermodynamically unfavorable, making the accurate twist angle control in direct growth implausible. While rotationally aligned moiré superlattices based on lattice-mismatched layers such as WSe2/WS2 can be synthesized, they lack the critical tunability of the moiré period and the moiré formation mechanisms are not well-understood. Here, we report the scalable, thermodynamically driven van der Waals epitaxy of stable moirés with tunable period from 10 to 45 nanometers, based on lattice mismatch engineering in two WSSe layers with adjustable chalcogens ratios. Contrarily to conventional epitaxy, where lattice mismatch induced stress hinders high-quality growth, we reveal the key role of bulk stress in moiré formation, as well as its unique interplay with edge stress in shaping the moiré growth modes. Moreover, the synthesized superlattices display tunable interlayer, and moiré intralayer excitons. Our studies unveil the unique epitaxial science of moiré synthesis and lay the foundations for moiré-based technologies.