Far-gate synaptic transistors utilizing ion-charge dual-transfer mechanism for neurotransmitter-multiplexing temporal coding

The ability of artificial synapses to replicate multiplexed-transmission is a significant advancement in emulating complex brain activities. However, it generally required more stringent material requirements of intrinsic-ambipolarity and more complex structures of P/N dual-channel. Here, we proposed a far-gate synaptic transistor (FGST) just using a single-channel composed of a common unipolar semiconductor to emulate the cooperation and competition between two excitatory neurotransmitters. FGST exhibits a unique ion-charge dual-transfer mechanism, enabling distinct behavioral regulation modes with switchable synaptic plasticity: ion-dominant potentiation-depression with short-term plasticity and hole-dominant potentiation with enhanced memory. Moreover, FGST with dual-excitatory enhancement can be used for temporal contrast encoding, dividing currents into multiple memory states based on a fixed threshold; by comparing the variations in postsynaptic currents with different thresholds, it offers a method for further expanding the number of temporal states in the device. This work is a step toward constructing multifunctional artificial intelligent systems.