Synaptic Plasticity and Learning Behavior Emulated in CuI-ITO Transistors

Synaptic transistors are fabricated using chitosan as the gate dielectric and CuI with sputtered ITO as the channel. Surface charge-transfer doping from the ITO enhanced the performance and operational stability of the devices. Meanwhile, the application of voltage pulses enables the devices to emulate synaptic characteristics, including excitatory postsynaptic currents (EPSCs), inhibitory postsynaptic currents (IPSCs), paired-pulse facilitation (PPF), short-term plasticity (STP), and spike-frequency-dependent plasticity (SFDP). Furthermore, the transistors exhibit the capacity to modulate synaptic weights bidirectionally by realizing both long-term potentiation (LTP) and long-term depression (LTD), with good repeatability. The biomimetic synaptic properties of the devices enable them to emulate the learning behaviors observed in biological systems. These findings highlight the potential of CuI-ITO transistors in neuromorphic applications that demand adaptive learning and real-time signal processing, thereby offering a promising pathway toward the advancement of artificial intelligence systems.