Reconfigurable Multifunctional Semifloating Gate Transistors Based on the ReSe₂/h-BN/Graphene van der Waals Heterostructure

In the post-Moore era, semifloating gate devices have great potential to be developed into next-generation devices for their excellent nonvolatile memory and reconfigurable logic. 2D materials have been focused due to their atomically flat surfaces, high carrier mobility, and excellent photoelectrical response. The 2D ReSe₂ is selected as a channel material for its ambipolar characteristic and outstanding optoelectronic response. Here, we fabricated ReSe₂/h-BN/Gr multifunctional semifloating gate (MFSFG) devices, which can work as bidirectional nonvolatile reconfigurable multistate P-N and N-P homojunctions, photodetectors, and artificial synaptic, reconfigurable logical, and half-wave rectification devices. The device exhibits large rectification ratios of ∼10⁶ (P-N) and ∼10⁴ (N-P) with great endurance (1000 cycles) and retention (1000 s). As a photodetector, it obtains the highest responsivity and detectivity of 1.98 A W^-1 and 6.39 × 10¹² Jones (N-P) and 0.93 A W^-1 and 2.00 × 10¹² Jones (P-N), respectively, under 532 nm illumination. The synaptic plasticity is perfectly achieved, and the convolutional neural network built based on synaptic data has the highest classification recognition accuracies of 96.54 and 88.99%. The logical ″XOR″, ″XNOR″, ″NAND″, ″OR″, and half-wave rectification functions are achieved on a single device under photoelectrical hybrid regulations. The integration of these various functions into a single ReSe₂/h-BN/Gr MFSFG device not only broadens the possibilities for utilizing 2D materials in multifunctional devices but also opens up new avenues for their application in neuromorphic computing and logic-in-memory chips.