Song, Okin Rhee, Dongjoon Kim, Jihyun Jung, Myeongjin Kim, Sunkook Kim, In Soo KANG, JOOHOON 2024-01-12T06:34:37Z 2024-01-12T06:34:37Z 2023-11-21 2024-05 1077-260X https://pubs.kist.re.kr/handle/201004/79853 Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have shown promise as a class of optoelectronic material for flexible photosynaptic devices. However, widespread use of 2D TMDCs has been limited because producing high-quality, large-scale films on flexible substrates has still been challenging. Herein, we propose a facile solution processing strategy to realize large-scale arrays of flexible photosynaptic devices based on 2D TMDCs. Bulk molybdenum disulfide (MoS2) crystals were first electrochemically exfoliated into few-layer nanosheets using molecular intercalants, followed by dispersion in isopropyl alcohol for spin coating on flexible substrates. Large lateral size of the nanosheets along with good wettability of the dispersion enabled the formation of continuous MoS2 nanosheet networks for scalable device fabrication. Sulfur vacancies within the MoS2 channel served as trapping sites for photogenerated carriers and supported photocurrent retention characteristics needed to mimic synaptic functions. The device array successfully demonstrated reinforcement learning capabilities for image recognition under repeated optical pulse signals. Finally, the optoelectronic performance was fairly stable under mechanical bending because devices did not crack or delaminate from the substrate. English Institute of Electrical and Electronics Engineers Solution-Processed 2D Transition Metal Dichalcogenide Networks for Scalable, Flexible Photosynaptic Device Arrays Article 10.1109/jstqe.2023.3307515 1 IEEE Journal on Selected Topics in Quantum Electronics, v.30, no.3, pp.1 - 11 IEEE Journal on Selected Topics in Quantum Electronics 30 3 1 11 N scie scopus 001179348600012 Engineering, Electrical & Electronic Quantum Science & Technology Optics Physics, Applied Engineering Physics Optics Article MOS2 EXFOLIATION MEMORY Sulfur Molybdenum Substrates Scanning electron microscopy Nanoscale devices Optical device fabrication Optical pulses 2D semiconductor artificial photosynapse flexible electronics optoelectronics solution processing