A New Effect of Oxygen Plasma on Two-Dimensional Field-Effect Transistors:Plasma Induced Ion Gating and Synaptic Behavior

作     者：Cheng-Lei Guo Bin-Bin Wang Wei Xia Yan-Feng Guo Jia-Min Xue 郭成磊;王斌斌;夏威;郭艳峰;薛加民

作者机构：Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 School of Physical Science and Technology ShanghaiTech University Shanghai 201210 Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100049 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2019年第36卷第7期

页      面：116-120页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：Supported by the National Key Research and Development Program of China under Grant No 2017YFA0305400 the ShanghaiTech University,and the Natural Science Foundation of Shanghai under Grant No 17ZR1443300 

主　　题：Plasma treatment is a powerful two-dimensional materials realizing neuromorphic devices 

摘      要：Plasma treatment is a powerful tool to tune the properties of two-dimensional materials. Previous studies have utilized various plasma treatments on two-dimensional materials. We find a new effect of plasma treatment. After controlled oxygen-plasma treatment on field-effect transistors based on two-dimensional SnSe2, the capacitive coupling between the silicon back gate and the channel through the 300 nm SiO2 dielectric can be dramatically enhanced by about two orders of magnitude(from 11 n F/cm^2 to 880 nF/cm^2), reaching good efficiency of ionliquid gating. At the same time, plasma treated devices show large hysteresis in the gate sweep demonstrating memory behavior. We reveal that this spontaneous ion gating and hysteresis are achieved with the assistance of a thin layer of water film automatically formed on the sample surface with water molecules from the ambient air, due to the change in hydrophilicity of the plasma treated samples. The water film acts as the ion liquid to couple the back gate and the channel. Thanks to the rich carrier dynamics in plasma-treated two-dimensional transistors, synaptic functions are realized to demonstrate short-and long-term memories in a single device. This work provides a new perspective on the effects of plasma treatment and a facile route for realizing neuromorphic devices.