Angle-Dependent Oscillatory Interlayer Coupling in Twisted MoS2/TaSe2 Heterostructure

Interlayer coupling plays a crucial role in the electronic band structures and optoelectronic properties of the two-dimensional (2D) twisted heterostructures. Herein, MoS2/TaSe2 heterostructures with different twist angles were successfully obtained using a polydimethylsiloxane (PDMS)-water-assisted transfer method. Low-frequency Raman scattering analysis demonstrates that the twist angles in the MoS2/TaSe2 heterostructure exhibit periodic regulation on the interlayer coupling, with relatively strong coupling observed at 0° and 60°. Furthermore, it was found that the intensity ratio of A to B excitons and the second harmonic generation (SHG) responses of the twisted MoS2/TaSe2 heterostructures show periodic and oscillatory features with the increase of the twist angles. These findings can be attributed to the periodic changes in layer spacing as the twist angle increases, which further changes the interlayer coupling in heterostructures. The controlling interlayer interactions through twist angles is significant for the practical design and application of optoelectronic devices based on twisted transition metal dichalcogenides (TMDs) heterostructures.