基于电化学掺杂聚合物发光场效应管的研究

Organic light-emitting field-effect transistors(OLETs), which combine display pixels and drive units in one device, not only great applications in flat panel displays, but also show great potential in electrically-pumped organic lasers. OLETs have been demonstrated in a wide range of organic materials including ?-conjugated molecules and polymers. This project focuses on OLETs based on electrochemically-doped polymers since polymers have the disadvantage of low mobility and current density. The investigation of light-emitting electrochemical cells has demonstrated that electrochemically-doped polymers possess higher carrier mobility and charge density. Double-layered OLETs with one layer for light emission and the other for carrier transport will be fabricated. Electrochemical doping of polymers and the distribution of an internal electrical field will be investigated under triple-electrodes driving. The influence of electrolytes, salts, and their doping concentration on the device performance in the situation of frozen ions at low temperatures will be revealed. The dependence of interfacial morphology and the corresponding energy band structure on electric field effects and the luminescent efficiency will be studied. The ASE process will also be explored. And finally, some salts will be directly doped into polymers to carry out electron/hole current at room temperature through freezing ions in order to obtain stable devices.

有机发光场效应晶体管在平板显示领域有明确的应用背景，可实现显示像素与驱动单元的集成。此外，该器件也被业内认为最可能用来实现有机电泵浦激光。本项目针对有机聚合物材料载流子迁移率低，传输电荷密度小等劣势，采用电化学掺杂聚合物为发光场效应管的传输层。LEC器件研究结果表明，电化学掺杂聚合物具有常规方法难以获得的电荷输运能力和电荷密度。利用传输层与发光层结合，采用双功能层结构制备发光场效应管，研究三工作电极时，聚合物电化学掺杂及器件内电场的分布；研究低温下，离子电导被'冻结'住后各种参数如聚合物电解质及盐的种类，掺杂度对器件性能的影响；研究各层之间界面形貌，能级匹配对器件场效应性能及发光效率的影响规律。尝试该结构器件实现ASE；最后采用高玻璃化温度聚合物电解质或放弃聚合物电解质，直接在聚合物半导体中掺杂盐的方法尝试实现室温下只有电子（空穴）电流，'冻结'住离子迁移的稳定器件。

聚合物晶体管是近年来有机光电子器件领域一个重要的研究方向。本项目首先将弱极性交联聚合物与强极性聚合物相结合组成低k/高k双层介电层，显著提高了聚合物晶体管性能。同时，本研究提出了将底层聚合物的正交溶剂和顶层聚合物的良溶剂相结合制备活性层，显著提高了双层聚合物晶体管器件性能。本项目还将有机无机杂化钙钛矿纳米片引入到聚合物晶体管的活性层中，制备了混合半导体薄膜为沟道材料的场效应晶体管，将器件的空穴迁移率提高了两个数量级。此外，本项目还在聚合物介电层上制备了高性能的二维钙钛矿场效应晶体管。最后，本项目研究了电化学晶体管的特性及相关影响因素，并成功制备了发光电化学晶体管。