A prototype of a 2D ferroelectric memory device is demonstrated. The nonvolatile functionality stems from the room‐temperature out‐of‐plane ferroelectricity in ultrathin α‐In2Se3. The hybrid ferroelectric field‐effect transistor allows not only the control and probe of electric dipoles, but also the quantitative measurement of the electric polarization in atomically thin van der Waals ferroelectrics. Abstract High‐density memory is integral in solid‐state electronics. 2D ferroelectrics offer a new platform for developing ultrathin electronic devices with nonvolatile functionality. Recent experiments on layered α‐In2Se3 confirm its room‐temperature out‐of‐plane ferroelectricity under ambient conditions. Here, a nonvolatile memory effect in a hybrid 2D ferroelectric field‐effect transistor (FeFET) made of ultrathin α‐In2Se3 and graphene is demonstrated. The resistance of the graphene channel in the FeFET is effectively controllable and retentive due to the electrostatic doping, which stems from the electric polarization of the ferroelectric α‐In2Se3. The electronic logic bit can be represented and stored with different orientations of electric dipoles in the top‐gate ferroelectric. The 2D FeFET can be randomly rewritten over more than 105 cycles without losing the nonvolatility. The approach demonstrates a prototype of rewritable nonvolatile memory with ferroelectricity in van der Waals 2D materials.
Published in: "Advanced Functional Materials".