Ferroelectric Field-Effect Transistors Based on WSe₂/CuInP₂S₆ Heterostructures for Memory Applications

Emerging data-intensive applications need to process data in situ by combining the logical operations and data storage in a single chip. In this work, the high-quality bulk CuInP2S6 (CIPS) and WSe2 crystals were synthesized by the chemical vapor transport method, with the ferroelectric properties of the CIPS flakes proven by piezoresponse force microscopy and electrical polarization–voltage (P–V) measurement. We then fabricated ferroelectric field-effect transistors (FeFETs) based on WSe2/CIPS heterostructures with a buried-gated architecture, which exhibited a clear clockwise hysteresis loop with an on/off current ratio exceeding 105 in transfer characterization. More than 100 endurance cycles and 50 s of retention were achieved, showing quasi-nonvolatile memory characteristics. Additionally, a memory ternary inverter circuit of a WSe2 FeFET serially connected to a MoS2 FET was fabricated, in which the three logic states (1, 1/2, and 0) could be clearly observed and voltage hysteresis characteristics with a memory window equal to that of a WSe2 FeFET were achieved. These results pave the way for the realization of integrating data storage with low-power logic on a single chip.