Conjugated Polymer‐Wrapped Single‐Wall Carbon Nanotubes for High‐Mobility Photonic/Electrical Fully Modulated Synaptic Transistor

Abstract

Although synaptic devices have already demonstrated their operability through electric or photonic signals or a combination thereof, current challenges include developing a single hardware synaptic device that is independently fully operational through either photonic or electric signals to improve device versatility. Additionally, most previously reported devices are fabricated using multiple technical processes—which impede device implementation—while the low‐output current triggered in most such devices limits the possible integration of auxiliary gadgets. Therefore, by spontaneously wrapping a conjugated block copolymer around single‐walled carbon nanotubes (SWCNTs), a thin‐film transistor memory device comprising single‐layered poly(9,9‐dioctylfluorene)‐b‐polyisoprene (PF‐b‐PI)‐wrapped‐SWCNTs—which function as both a semiconductor and an electret layer—to simplify the device structure and fabrication is designed. Owing to the robust SWCNT charge carrier mobility (≈11.3 cm2 V−1 s−1), a high output current (10−4 to 10−3 A) can be achieved and because PF is a photoactive conjugated polymer, the photonic signal can also be modulated. The designed memory device independently exhibits both voltage‐ and light‐controllable switching, thereby mimicking biological synaptic behavior such as short‐ and long‐term plasticity, spike‐time, and spike‐rate‐dependent plasticity. This study may provide a suitable basis for developing more‐convenient, economical, highly versatile synaptic devices.