Université de Strasbourg, CNRS, ISIS, 8 allée Gaspard Monge, Strasbourg, 67000, France.
School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 101408, P. R. China.
Adv Mater. 2022 Dec;34(50):e2205945. doi: 10.1002/adma.202205945. Epub 2022 Nov 2.
Neuromorphic engineering and artificial intelligence demands hardware elements that emulates synapse algorithms. During the last decade electrolyte-gated organic conjugated materials have been explored as a platform for artificial synapses for neuromorphic computing. Unlike biological synapses, in current devices the synaptic facilitation and depression are triggered by voltages with opposite polarity. To enhance the reliability and simplify the operation of the synapse without lowering its sophisticated functionality, here, an electrochemical-electret coupled organic synapse (EECS) possessing a reversible facilitation-to-depression switch, is devised. Electret charging counterbalances channel conductance changes due to electrochemical doping, inducing depression without inverting the gate polarity. Overall, EECS functions as a threshold-controlled synaptic switch ruled by its amplitude-dependent, dual-modal operation, which can well emulate information storage and erase as in real synapses. By varying the energy level offset between the channel material and the electret, the EECS's transition threshold can be adjusted for specific applications, e.g., imparting additional light responsiveness to the device operation. The novel device architecture represents a major step forward in the development of artificial organic synapses with increased functional complexity and it opens new perspectives toward the fabrication of abiotic neural networks with higher reliability, efficiency, and endurance.
神经形态工程和人工智能需要模拟突触算法的硬件元件。在过去的十年中，电解质门控有机共轭材料一直被探索作为神经形态计算用人工突触的平台。与生物突触不同，在当前的器件中，突触易化和抑制是由极性相反的电压触发的。为了提高可靠性并简化操作而不降低其复杂功能，本文设计了一种具有电化学-驻极体耦合的有机突触（EECS），它具有可逆的易化到抑制的转换。驻极体充电抵消了电化学掺杂引起的沟道电导变化，从而在不反转栅极极性的情况下产生抑制。总的来说，EECS 作为一种由其幅度相关的双模态操作控制的门控突触开关，其功能类似于真实突触中的信息存储和擦除。通过改变沟道材料和驻极体之间的能级偏移，可以调整 EECS 的转换阈值，以满足特定应用的需求，例如为器件操作赋予额外的光响应能力。该新型器件结构代表了在开发具有更高功能复杂性的人工有机突触方面的重大进展，并为制造具有更高可靠性、效率和耐久性的非生物神经网络开辟了新的前景。
