From memristor to synaptic transistor: progress of three-terminal organic synapse in material and neuromorphic application

Brain-like synaptic electronics represent a promising avenue for next-generation information technology, addressing the limitations of conventional von Neumann architectures. Compared with existing CMOS-based neuromorphic hardware, highly scalable artificial synaptic device units offer superior computational energy efficiency and have consequently attracted extensive research interest. This review provides a detailed discussion of the operational mechanisms and neuromorphic characteristics of memristor-based and transistor-based artificial synapses, tracing their structural evolution from two-terminal to three-terminal configurations. With a particular focus on organic electrochemical synaptic transistors—noted for their significant application potential—we have comprehensively summarized their material systems and state-of-the-art neuromorphic applications. Furthermore, we analyze the current limitations and outline prospective optimization strategies for these devices. In summary, our work surveys the developmental trajectory and recent technological breakthroughs in artificial synapses, thereby providing foundational insights for the advancement of neuromorphic electronics.