Gate‐Tunable Synaptic Plasticity through Controlled Polarity of Charge Trapping in Fullerene Composites

Motivated by the biological neuromorphic system with high degree of connectivity to process huge amounts of information, transistor‐based artificial synapses are expected to pave a way to overcome the von Neumann bottleneck for neuromorphic computing paradigm. Here, artificial flexible organic synaptic transistors capable of concurrently exhibiting signal transmission and learning functions are verified using C60/poly(methyl methacrylate) (PMMA) hybrid layer for the first time. C60 trapping sites are doped in PMMA by facile solution process to form the hybrid structure. The flexible synaptic transistor exhibits a memory window of 2.95 V, a currenton/currentoff ratio greater than 103, program/erase endurance cycle over 500 times. In addition, comprehensive synaptic functions of biosynapse including the excitatory postsynaptic current with different duration time, pulse amplitudes and temperatures, paired‐pulse facilitation/depression, potentiation and depression of the channel conductance modulation, transition from short‐term potentiation to long‐term potentiation, and repetitive learning processes are successfully emulated in this synaptic three‐terminal device. The realization of synaptic devices based on C60 with low operation voltage and controlled polarity of charge trapping is an important step toward future neuromorphic computing using organic electronics. Artificial flexible organic synaptic transistors capable of concurrently exhibiting signal transmission and learning functions are verified using C60/poly(methyl methacrylate) hybrid layer for the first time. The continuous semiconducting channel modulation and essential functions of an artificial synapse, including excitatory postsynaptic current, paired‐pulse facilitation, paired‐pulse depression, short‐term potentiation, long‐term potentiation as well as repetitive learning and forgetting processes are successfully achieved.