双金属Cu@Ag核壳纳米线透明薄膜电极的制备、改性及导电机制研究

Metal nanowire transparent electrode is one of the hottest candidates for the transparent electrodes of the next generation optoelectronic devices, due to its excellent photoelectrical properties, be lightweight, flexible, cheap and compatible with large-scale manufacturing methods. Considering the advantages of monometallic nanowire transparent electrode, we plan to propose an emerging bimetallic Cu@Ag core-shell nanowire electrode. By investigating the structures and morphologies of the nanowires, the concentration of the nanowires in the film, the thickness of the films and the modification of electrodes, we will reveal the relevance between the physical characteristics and the properties of the transparent nanowire electrode. The characteristics include the light scattering, interfacial electron transport and work function of the electrode. In addition, we plan to fabricate the polymer solar cells on the surface of the Cu@Ag core-shell nanowire electrode, and characterized the properties of the solar cells. This is aimed to perceive the compatibility of the electrode and organic active layer in the solar cell, the characteristic of the carrier transport, the chemical stability and so on. Finally, we will clarify the conduction mechanism of the Cu@Ag core-shell nanowire electrode, and fabricate one emerging transparent electrode which can replace ITO and show the controllable work function, high transparency and conductivity, low film roughness. The research could provide important experimental and theoretical guidance for optimizing performance of the optoelectronic devices, and accelerate the process of the development for the next generation optoelectronic devices.

金属纳米线透明电极由于光电性能优异，且轻薄柔软、成本低廉，适应大规模生产而成为新一代光电器件透明电极的热点选择之一。本项目结合单金属纳米线透明电极的优点，提出一种新型双金属Cu@Ag核壳纳米线透明电极。旨在通过研究双金属纳米线的结构、形貌、薄膜所含纳米线浓度、薄膜厚度、电极改性处理等诸多参数，揭示电极的光散射、界面电子输运和功函数等物理特性与电极性能的关联机制；并基于此电极表面构建典型聚合物太阳能电池，通过测试电池性能以探索电极与有机活性层的膜层匹配性、载流子输运及化学稳定性等物理特性，最终阐明双金属Cu@Ag核壳纳米线透明电极的导电机制，获得一种功函数可调控，具有高透过高电导和低表面粗糙度的，可取代传统透明电极ITO的新型透明薄膜电极。此研究可为优化光电器件性能提供重要的实验及理论依据，对促进光电器件的更新换代具有重大的社会意义与经济价值。

透明薄膜电极在显示技术、绿色能源利用等重要的国民经济领域具有广泛的应用，而新一代的光电器件要求透明电极轻薄柔软、成本低廉且能适应大规模生产。因此，传统透明电极材料ITO受到应用的限制。金属纳米线透明导电薄膜，由于其具有优良的光电性能，制备工艺可采用成本低廉的液相法，且与低熔点的柔性衬底具有良好的兼容性等优点，成为有望取代ITO的新型透明电极之一。本项目在以下几个方面取得阶段性的研究成果：（1）金属纳米线与有机物（PVA、PMMA、PI、PDMS等）复合薄膜的构建及性能研究，利用机械层压及转移法有效提高金属纳米线导电网络的联通性，降低薄膜面电阻和表面粗糙度，增强导电网络对基底的附着力。（2）双金属纳米线的合成及表征，利用金属之间的化学电势差制备了双金属核壳纳米结构（Cu@Ag、Ag@Pt和Ag@Au等），通过控制反应条件，可制备包覆均匀的双金属纳米线，此结构能有效提高单金属纳米线的化学稳定性。（3）金属纳米线基透明电极在柔性光电器件中的应用，如在电致变色器件、电加热薄膜器件和压力/拉力传感器件中都得到成功应用。通过测试器件性能获知电极与活性层的膜层匹配性、载流子输运及化学稳定性等特性，最终获得具有优异光电性能、高稳定性、低表面粗糙度和高附着力的金属纳米线基透明电极。此研究可为优化光电器件性能提供重要的实验及理论依据，对促进光电器件的更新换代具有重大的社会意义与经济价值。