Nonvolatile memristor based on heterostructure of 2D room-temperature ferroelectric α-In2Se3 and WSe2

Two-dimensional (2D) ferroelectricity is considered to have significant potential for information storage in the future. Semiconducting ferroelectrics that are stable at room temperature afford many possibilities for the assembly of various high-performance heterostructures and fabricating multifuntional devices. Herein, we report the synthesis of a stable van der Waals (vdW) single-crystal semiconductor alpha-In2Se3. Piezoresponse force microscopy (PFM) measurements demonstrated the out-of-plane ferroelectricity in similar to 15 layers alpha-In2Se3 at room temperature. Both ferroelectric domains with opposite polarization and the tested amplitude and phase curve proved that this semiconductor exhibits hysteresis behavior during polarization. In the alpha-In2Se3/WSe2 vertical heterostructure device, the switchable diode effect and nonvolatile memory phenomenon showed a high on/off ratio and a small switching voltage. The distinct resistance switches were further analyzed by band alignment of the heterostructure under different polarizations by first principle calculations. Nonvolatile memory based on vdW ferroelectric heterostructure could provide a novel platform for developing 2D room-temperature ferroelectrics in information storage.