Electroplasticity Memory Device Using Conducting Polymer and Electrolyte Gel

准一维半导体导电聚合物可通过电化学方法在聚合物链间可重复掺杂氧化还原剂，由半导体转化为金属导体。利用这一特性制备了电塑性记忆器件，并对输入信号响应和记忆特性进行了研究。制备了3电极和2电极两种类型的记忆器件，其记忆通道由聚3-甲基噻吩导电聚合物构成。采用聚氧聚乙烯、环氧丙烷共聚物和LiCl04作为固体聚合物电解质，构建了与传统场效应晶体管类似的微电化学电池。在源极和漏极之间电化学合成聚3-甲基噻吩，并在其上粘贴固体聚合物电解质。对于三电极装置，锂的输入电极被压在固体电解质上。测量了电势扫描和脉冲电压等输入信号对通道电导率的响应。从实验结果来看，设备在两种信号的作用下都达到了预期的效果，并显示出具有学习效果的记忆功能。研究还发现，通道电导率与脉冲电压的大小和脉冲频率有关。这些器件的特性是无机半导体所不能达到的，类似于神经网络的突触可塑性。改进响应时间、记忆特性和构建信号处理系统是进一步研究的课题。

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.