ASIC and System State Key Lab., School of Microelectronics, Fudan University, Shanghai, 200433, China.
National Laboratory of Solid State Microstructures, School of Electronic and Engineering, and Collaborate Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
Adv Mater. 2019 Jan;31(3):e1806227. doi: 10.1002/adma.201806227. Epub 2018 Nov 28.
Just as biological synapses provide basic functions for the nervous system, artificial synaptic devices serve as the fundamental building blocks of neuromorphic networks; thus, developing novel artificial synapses is essential for neuromorphic computing. By exploiting the band alignment between 2D inorganic and organic semiconductors, the first multi-functional synaptic transistor based on a molybdenum disulfide (MoS )/perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) hybrid heterojunction, with remarkable short-term plasticity (STP) and long-term plasticity (LTP), is reported. Owing to the elaborate design of the energy band structure, both robust electrical and optical modulation are achieved through carriers transfer at the interface of the heterostructure, which is still a challenging task to this day. In electrical modulation, synaptic inhibition and excitation can be achieved simultaneously in the same device by gate voltage tuning. Notably, a minimum inhibition of 3% and maximum facilitation of 500% can be obtained by increasing the electrical number, and the response to different frequency signals indicates a dynamic filtering characteristic. It exhibits flexible tunability of both STP and LTP and synaptic weight changes of up to 60, far superior to previous work in optical modulation. The fully 2D MoS /PTCDA hybrid heterojunction artificial synapse opens up a whole new path for the urgent need for neuromorphic computation devices.
正如生物突触为神经系统提供基本功能一样，人工突触器件是神经形态网络的基本构建块；因此，开发新型人工突触对于神经形态计算至关重要。通过利用二维无机和有机半导体之间的能带排列，首次报道了基于二硫化钼（MoS ）/苝-3,4,9,10-四羧酸二酐（PTCDA）杂化异质结的多功能突触晶体管，具有显著的短期可塑性（STP）和长期可塑性（LTP）。由于能带结构的精心设计，通过异质结构界面的载流子转移实现了稳健的电和光调制，这至今仍是一项具有挑战性的任务。在电调制中，通过栅极电压调谐可以在同一器件中同时实现突触抑制和兴奋。值得注意的是，通过增加电数，可以获得 3%的最小抑制和 500%的最大促进，并且对不同频率信号的响应表明具有动态滤波特性。它表现出 STP 和 LTP 的灵活可调性以及高达 60 的突触权重变化，远优于光学调制方面的先前工作。完全二维的 MoS /PTCDA 杂化异质结人工突触为迫切需要的神经形态计算设备开辟了全新的途径。
