Optically excited threshold switching synapse characteristics on nitrogen-doped graphene oxide quantum dots (N-GOQDs)

JOURNAL OF ALLOYS AND COMPOUNDS

卷:855

Article

Ali, Mumtaz¹  Sokolov, Andrey²  Ko, Min Jae³  Choi, Changhwan² 

[1] Hanyang Univ, Dept Organ & Nano Engn, Seoul 04763, South Korea

[2] Hanyang Univ, Div Mat Sci & Engn, Seoul 04763, South Korea

[3] Hanyang Univ, Dept Chem Engn, Seoul 04763, South Korea

关键词: Graphene oxide;    Light stimulation;    Diffusive memristor;    Threshold switching;    Synapse device;   

DOI  :  10.1016/j.jallcom.2020.157514

来源: Elsevier

【 摘 要 】

Carbon-based organic material such as nitrogen-doped graphene oxide quantum dots (N-GOQDs) is a new-class material with unique biocompatible, high chemical inertness, and elevated photoluminescence properties. Two-terminal diffusive memristors can faithfully replicate biological synapse function via mutual similarities of in-/out-diffusion of Ag+ ions with biological Ca2+ migration dynamics for neural network applications. Inspired by hetero-plasticity phenomenon, in which Ca2+ dynamics can also be tuned by the 3rd counterpart - neuromodulatory axon, in this study, using an ultra-violet light source, we develop N-GOQDs based diffusive memristor that performs light-modulated synaptic behaviors. Specifically, photo-sensitive N-GOQDs ionic conductor shows n-pi* electron transitions under UV excitation; yet, nitrogen-doping further facilitates the electron transitions, giving out additional conductance induced by light. Further, we demonstrate endurable threshold resistive switching (TS) behavior based on Ag+ ions migration and its variety of facilitations via assisted UV illumination. The enhancement of post-synaptic current under assisted UV light, as well as the light stimulated transition from short-to long-term memory potentiation have been achieved. These findings are believed to be a step forward for the realization of higher bandwidth synapse modulation as future hardware-based neural network applications. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

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