Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology, Fuzhou University, Fuzhou 350002, People's Republic of China. Zhicheng College, Fuzhou University, Fuzhou 350002, People's Republic of China.
Nanotechnology. 2020 May 22;31(21):215202. doi: 10.1088/1361-6528/ab7252. Epub 2020 Feb 3.
Artificial intelligence devices that can mimic human brains are the foundation for building future artificial neural networks. A key step in mimicking biological neural systems is the modulation of synaptic weight, which is mainly achieved by various engineering approaches using material design, or modification of the device structure. Here, we realize the modulation of the synaptic weight of a TaO/ITO-based all-metal oxide synaptic transistor via laser irradiation. Prior to the deposition of the active layer and electrodes, a femtosecond laser was used to irradiate the surface of the insulator layer. Typical synaptic characteristics such as excitatory postsynaptic current, paired pulse facilitation and long-term potentiation were successfully simulated under different laser intensities and scanning rates. In particular, we demonstrate for the first time that laser irradiation could control the quantity of oxygen vacancies in the TaO thin film, leading to precise modulation of the synaptic weight. Our research provides an instantaneous (<1 s), convenient and low-temperature approach to improving synaptic behaviors, which could be promising for neuromorphic computing hardware design.
能够模拟人脑的人工智能设备是构建未来人工神经网络的基础。模拟生物神经网络的关键步骤是调节突触权重，这主要通过使用材料设计或修改器件结构的各种工程方法来实现。在这里，我们通过激光辐照实现了基于 TaO/ITO 的全金属氧化物突触晶体管的突触权重调节。在沉积活性层和电极之前，使用飞秒激光辐照绝缘体层的表面。在不同的激光强度和扫描速率下，成功地模拟了典型的突触特性，如兴奋性突触后电流、成对脉冲易化和长时程增强。特别是，我们首次证明激光辐照可以控制 TaO 薄膜中的氧空位数量，从而实现对突触权重的精确调节。我们的研究提供了一种瞬时（<1 秒）、方便且低温的方法来改善突触行为，这对于神经形态计算硬件设计具有广阔的应用前景。
