Simultaneous Dual‐Plasticity Organic Synaptic Transistor for Neuromorphic Computing

ABSTRACT Neuromorphic computing systems require artificial synaptic devices capable of emulating complex biological neural functions. This study presents a dinaphtho[2,3‐b:2′,3′‐f]thieno[3,2‐b]thiophene (DNTT)‐based organic field‐effect transistor that demonstrates synaptic plasticity under optical stimulation at 200 K. The device exhibits a dual‐mechanism synaptic behavior through charge separation and trapping, where photogenerated holes provide rapid transport while electrons are preferentially captured in deep trap states, creating persistent field modulation. Excitatory postsynaptic current measurements reveal characteristic three‐phase temporal dynamics with rapid activation, exponential decay, and sustained enhancement lasting tens of minutes. Paired‐pulse facilitation demonstrates short‐term plasticity with dual exponential decay constants of 140 and 610 ms, while multi‐pulse stimulation produces remarkable persistent current level enhancement exceeding 10 000% of the initial baseline, reflecting sequential filling of continuous trap state distributions. The device simultaneously implements both short‐term and long‐term plasticity mechanisms in a single component, enabling simultaneous working memory and persistent information storage functions. Neuromorphic functionality is demonstrated through simulated XOR logic operations, showing non‐linearly separable computation capabilities. The 200 K operating temperature aligns favorably with Mars surface conditions, requiring minimal heating compared to terrestrial cooling requirements, making the device particularly promising for space‐based neuromorphic systems where radiation‐hard organic semiconductors provide additional advantages.