Reconfigurable Floating-Gate Devices with Ambipolar ReSe₂ Channel: Dual-Mode Storage, NMOS-PMOS Transformation, Logic Functions, Synapse Simulations, Positive and Negative Photoconductive Effects

2D floating-gate (FG) devices with reconfigurable functions are gradually replacing traditional FG devices, and are highly likely to become the core components in future integrated sensing-memory-computation (SMC) chips. Only the traditional 2D FG devices with complex structures can achieve reconfigurable functions. In this work, a reconfigurable multifunctional floating-gate (MFFG) device is proposed with the simple ReSe₂/h-BN/Gr heterostructure full FG structure, integrating a plethora of functions, including non-volatile dual-mode storage and dynamic NMOS-PMOS transformation, non-volatile and volatile photoelectric memory, frequency doubling and reconfigurable logic of “AND”, “NOR”, and “XNOR”. The ambipolar properties of 2D ReSe₂ facilitate the continuous write and erase using single polarity pulses. This device shows impressive performance metrics, with large memory windows (>70%), high reading current on/off ratios (>10⁴), exceptional endurance (>3000 cycles), and retention (>1000 s) in both P-type and N-type memory modes. The symmetrical dual-mode storage effectively enhances multi-state storage capacity to 120 states. A more unique characteristic is the coexistence of non-volatile negative photoconductivity and volatile positive photoconductivity. Furthermore, the high recognition accuracies (96.5% for MNIST and 89.2% for F-MNIST) show great development potential for MFFG device as artificial synapse. The excellent performance of the MFFG device expands its application prospect in next-generation SMC chips.