Electroplasticity Memory Device Using Conducting Polymer and Electrolyte Gel

准一维半导体导电聚合物可以通过电化学法在聚合物链间加入氧化剂和还原剂进行重复掺杂和非掺杂，从半导体转变为金属导体。利用这一新特性，制作了电塑性存储器件，并研究了其对输入信号的响应和存储特性。制作了3电极和2电极两种类型的存储器件，存储沟道由聚3-甲基噻吩型导电聚合物组成。微电化学池类似于常规场效应晶体管，由聚氧乙烷和环氧丙烷与LiCl04共聚的固体聚合物电解质构成。在源漏极间电化学合成了聚(3-甲基噻吩基)，并在其上粘贴了固体聚合物电解质。对于三电极器件，将Li的输入电极压在固体电解液上，测量了输入信号如电位扫描和脉冲电压对通道电导的响应。从实验结果来看，该装置在两种信号的作用下都达到了预期的效果，表明该装置具有记忆功能和学习效果。研究还发现，沟道电导率依赖于脉冲电压的大小和脉冲的频率。这些器件的特性是无机半导体无法实现的，类似于神经网络的突触可塑性。响应时间、记忆特性的改善和信号处理系统的构建是进一步研究的主题。

Conducting polymers of quasi-one-dimensional semiconductor can be reproducibly doped and undoped with oxidizing and reducing agents between polymer chains by electrochemical method and turns into metallic conductor from semiconductor. Using this novel property, the electroplasticity memory devices were fabricated, and the responses by input signals and memory characteristics were investigated.Two types of memory devices with 3-electrode and 2-electrode were fabricated the memory channel was composed with conducting polymer of poly(3-methylthiophene). Microelectrochemical cell was constructed similar to the conventional field effect transistor with solid polymer electrolyte of polyethylene oxide and propylene oxide co-polymer with LiCl04. The poly(3-methylthiophene was synthesized electrochemically between source and drain, on which the solid polymer electrolyte was pasted. For the case of 3-electrode device, the input electrode of Li was pressed on the solid electrolyte.The responses of the channel conductivity by the application of the input signals such as potential sweep and pulse voltage were measured. From the experimental results, the devices operated by the both signals as expected and indicated the memory function with learning effect. It is also found that the channel conductivity depended on the magnitude of pulse voltage and frequency of pulses. The characteristics of these devices can not be achieved by the inorganic semiconductors, are resembled to the synapse plasiticity of neural networks. The improvement of response time, memory characteristics and the construction of a signal process system are the subject of further investigations.