Controlling Spontaneously-Formed Nanoscrolls by In-Plane Janus TMD/Traditional TMD Heterostructures

Nanoscrolls derived from flat transition metal dichalcogenide (TMD) monolayers and their corresponding heterostructures exhibit considerable potential for applications in next-generation electronic and optoelectronic devices. However, a predictive theoretical framework for the precise structure of nanoscroll with in-plane heterostructure is currently lacking. In this work, we establish an analytical thermodynamic model based on energy minimization to describe the stable structure of nanoscrolls formed from in-plane Janus TMD/traditional TMD heterostructures with arbitrary number of segments. The model elucidates the roles of spontaneous curvature, bending stiffness, van der Waals interaction, compositional ratio and total length as the key controlling parameters for inner radius. For validation, we perform large-scale molecular dynamics (MD) simulations using a developed hybrid potential accounting for both intralayer and interlayer interactions, capturing the complete spontaneous scrolling process of the heterostructured nanoribbons. The inner radii obtained from MD simulations show agreement with the model. Furthermore, we extend the investigation from nanoribbons to nanoflakes with in-plane heterostructures to explore their scrolling dynamics and demonstrate the resultant complex morphologies. This work proposes a theoretical framework connecting material properties to nanoscroll structure, providing a guidance for the on-demand design of functional nanodevices based on nanoscrolls.