基于非晶碳纳米忆阻器的神经突触仿生器件研究

The resistance of a memristor changes with the amount of electric charges flowing through it. Moreover, the resistance can be retained as the bias voltage is removed. These features are highly similar to the working principle of neural synapses in biological brains. In addition, a memristive device is simple in structure thus having a high integration density. Therefore, the memristor has attracted much attention due to its potential application as novel biomimetic synapses. Till now, the memristive materials for synaptic devices mainly focus on oxides and chalcogenides. Compared to those materials, amorphous carbon (a-C) has a simple composition and it is easy to realize controllable preparation of a-C. At the same time, a-C shows good memristive behaviors. So, a-C-based memristive devices have unique advantages as biomimetic synapses. This project aims to find one or two a-C memristive materials with controllable multilevel resistance states, obtain stable crossbar-structured nanoscale a-C memristive devices with low energy consumption, and achieve controllable synaptic mimicry such as STDP learning rule and long-term/short-term plasticity, i.e., obtain a-C-based biomimetic synapses. Furthermore, this project aims to elucidate the working mechanism of a-C-based biomimetic synapses by employing the atmosphere, temperature and illumination tunable probe station for electrical measurements and in situ transmission electron microscopy technique.We possess independent intellectual property rights to all the materials and devices devoloped in this project.

忆阻器电阻值会随流经电荷量而发生改变，并且具有电阻记忆功能，这些特性与生物大脑中神经突触的工作原理高度相似，再加上其结构简单，集成度高，因此在新型神经突触仿生电子器件领域引起极大关注。目前，用于突触仿生器件的忆阻材料主要集中于氧化物及硫系物质,和它们相比，非晶碳（a-C）组分简单，易于可控制备，同时也具有优良的忆阻性能,因此，非晶碳忆阻器在作为突触仿生器件方面具有独特的优势和应用潜力。本项目旨在找到1-2种具有自主知识产权、能可控实现多电阻态的a-C忆阻材料，利用电子束刻蚀等方法制备出性能稳定、能耗低的交叉阵列结构a-C基纳米忆阻器件。在此基础上，通过合理设计电激励信号，实现突触功能的可控模拟，包括STDP学习能力和长短程记忆行为，获得具有自主知识产权的a-C基神经突触仿生器件。同时利用气氛、温度及光照可变电学测量探针台，结合可原位电学测试透射电镜，深入理解a-C突触器件的微观工作机制。

忆阻器的电学特性与生物大脑中神经突触的工作原理高度相似，并且其结构简单，可集成度高，因此在神经突触仿生器件领域引起极大关注。目前，用于突触器件的忆阻材料主要集中于氧化物及硫系物质,和它们相比，非晶碳（a-C）组分简单，易于可控制备，因此，非晶碳忆阻器在作为突触器件方面具有独特的优势。通过本项目研究，获得了具有自主知识产权、能可控实现多电阻态的a-C 忆阻材料，利用电子束蒸发等方法制备出性能稳定、能耗较低的a-C 基忆阻器件。在此基础上，通过合理设计电激励信号，实现突触功能的可控模拟，包括长程增强可塑性、长程抑制可塑性等，实现了a-C 基神经突触仿生器件。同时利用高分辨透射电镜、导电原子力显微镜等，深入理解了a-C 突触器件的微观工作机制。