Virtual Out-of-Plane Piezoelectric Response in MoS2 Layers Controlled by Ferroelectric Polarization

The MoS2 carrier distribution can be controlled with the use of a dielectric environment substrate. Ferroelectric thin films are used to investigate the electrical responses at the MoS2 layer. The MoS2/(111)-PbTiO3 vertical heterostructure is investigated, and the electrical responses, including piezoelectricity, are obtained using piezoresponse force microscopy. The piezoelectric response modifications obtained at the MoS2 layer on the ferroelectric thin films are a result of the depolarizing effect. In particular, the piezoelectricity enhancement is observed at the 19-layer MoS2 because of an induced dipole effect. By considering the polarization effects of ferroelectric thin films, the electrical responses at the MoS2 layers can be controlled, and the interfacial carrier distribution at the interface results in different electrical performances at the MoS2.