High-performance a MoS₂ nanosheet-based nonvolatile memory transistor with a ferroelectric polymer and graphene source-drain electrode

Two-dimensional (2D) van der Waals (vdWs) materials are a class of new materials due to their unique physical properties. Of the many 2D vdWs materials, molybdenum disulfide (MoS₂) is a representative n-type transition-metal dichalcogenide (TMD) semiconductor. Here, we report on a high-performance MoS₂ nanosheet-based nonvolatile memory transistor with a poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) ferroelectric top gate insulator. In order to enhance the ohmic contact property, we use graphene flakes as source/drain electrodes prepared by using the direct imprinting method with an elastomer stamp. The MoS₂ ferroelectric field-effect transistor (FeFET) shows the highest linear electron mobility value of 175 cm²/Vs with a high on/off current ratio of more than 10⁷, and a very clear memory window of more than 15 V. The program and erase dynamics and the static retention properties are also well demonstrated.