Van der Waals twistronics in a MoS2/WS2 heterostructure

The heterostructure of MoS2/WS2 is chosen as a model system to explore the role of interlayer twist on the structural, electronic, mechanical and optical properties. Extensive first-principles based calculations reveal that the formation of stable heterostructure at certain specific twisted angles at minimal interlayer strain, while the semiconducting phase varies between direct and indirect band gap structure in various configurations. The Young's modulus and Poisson's ratio of the heterostructure are well comparable to that of the individual monolayers, which indicate the flexibility of this heterostructure. Furthermore, the optical properties such as dielectric constant, absorption coefficient and optical conductivity are found to be strongly enhanced with twist, as compared to its constituent monolayers. The combined attributes suggest the usefulness of this heterostructure for optomechanical and optoelectronics applications in phase-tunable twistronics.