The development of neuromorphic systems necessitates the use of memcapacitors that can adapt to optoelectronic modulation. Two-dimensional (2D) materials with atomically thin features and their derived heterostructures are able to allow for controlling local transfer of charge carrier but reports on 2D materials-enabled capacitive-type photoelectric synapses have not been experimentally exploited yet. Herein, MXene-TiO2 heterostructured iontronic neural devices based on ion-dynamic capacitance enabling optoelectronic modulation are designed. According to the electrochemical insight, under UV light illustration, photoexcited electrons in TiO2 flow to MXene, leading to the localized accumulation of electrons as the trapping center and thus inducing the embedding of H+ for participating in the pseudo-intercalation. On removing the UV light, a part of trapped H+ are not instantly returned to the initial state. As a result, this memcapacitor features hysteresis ion-dynamic capacitance under optoelectronic modulation. Through assessing its applicability to neuromorphic computing, this memcapacitor achieves the high recognition accuracy (93.5%) of handwritten digits by recognizing and sharpening the input signal trajectory.

中文翻译：

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基于离子动态电容的 MXene-TiO2 异质结构电离子神经器件可实现光电调制


神经形态系统的发展需要使用能够适应光电调制的内存电容器。具有原子薄特征的二维 （2D） 材料及其衍生的异质结构能够控制电荷载流子的局部转移，但关于 2D 材料支持的电容型光电突触的报道尚未得到实验开发。在此，设计了基于离子动态电容的 MXene-TiO2 异质结构离子电子神经器件，使能光电调制。根据电化学见解，在紫外光下，TiO2 中的光激发电子流向 MXene，导致电子作为俘获中心的局部积累，从而诱导 H+ 的嵌入参与伪插层。去除紫外线后，被捕获的 H+ 的一部分不会立即恢复到初始状态。因此，该内存电容器在光电调制下具有磁滞离子动态电容。通过评估其对神经形态计算的适用性，该内存电容器通过识别和锐化输入信号轨迹，实现了手写数字的高识别准确率 （93.5%）。