Artificial optoelectronic synaptic devices based on vertical organic field-effect transistors with low energy consumption

Neuromorphic devices with ultra-low energy consumption are highly desired for artificial intelligence and brain-like computing. Here, artificial optoelectronic synaptic devices based on vertical organic field-effect transistors (VOFETs) are fabricated, in which the composite film of the poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl) thieno [3,2-b]thiophene)] and polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) is utilized as the active layer. SEBS is employed to reduce the possibility of source-drain short-circuiting during the device fabrication. Due to the VOFET structure, the device can work at low voltages because of the shorter charge carrier transport distance. Typical biological synaptic performances including excitatory postsynaptic current, short/long-term plasticity, and "learning experience" can be mimicked by the VOFET-based optoelectronic synaptic devices. Importantly, most synaptic functions can be achieved at a low voltage of -0.01 V, and the device still exhibits an obvious response even at an operating voltage of -0.001 V, achieving an ultra-low power consumption of similar to 0.12 fJ, which is among the best reported transistor-based synaptic devices. This work offers a new approach to fabricating neuromorphic electronic devices with ultra-low electric power consumption.