PEDOT:PSS纳米复合薄膜的可控构筑及其在有机聚合物太阳电池中的应用研究

Conductive polymer Poly(3, 4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) can be used as hole transport layer or conducting electrodes in organic solar cells (OSCs) owing to its outstanding optical/electrical properties, high work function and easy to improve conductivity by doping. But the conductive mechanism of PEDOT:PSS film after doping remains unclear. In addition to conductivity increase, other fundamental properties of modified PEDOT:PSS thin-film should conduct a systematic study to improve the efficiency of OSCs. This project intends to use nanocomposite technology, by adding different zwitterion in PEDOT:PSS solution or spin-coating them on the surface of PEDOT:PSS films, PEDOT:PSS nano-composite films with different electrical conductivity and surface/interface property will be prepared. We will use a variety of electron microscopy and spectroscopy characterization methods in combination with the theoretical calculation to study focused on surface morphology and internal structure changes after zwitterion modified. These results will not only help us to revealing conductivity and surface/interface property mechanism of PEDOT:PSS film after zwitterion modified , but establish an effective method to regulate the conductivity and surface/interface property of PEDOT: PSS film. We will investigate transport characteristics of electrons and holes on surface/interface of PEDOT: PSS films, explore influence mechanism between PEDOT:PSS nano-composite films and OSCs device performance. Our research project will provide well scientific theoretical basis for the development of low-cost and high-performance OSCs.

导电聚合物PEDOT:PSS具有优异的光学/电学性能、高的功函数和易于通过掺杂等方式提高电导率等优点，可作为界面层或导电电极用于有机太阳电池中，但其导电机制尚不清楚。除了电导率，薄膜其它性能对提高电池效率的影响有待系统研究。本项目拟采用纳米复合技术，通过在PEDOT:PSS溶液中添加或在薄膜表面旋涂不同的两性离子化合物，构筑具有不同电导率和表界面性能的PEDOT:PSS纳米复合薄膜；运用多种电镜和光谱表征手段，结合理论计算，重点研究两性离子化合物修饰后薄膜表面形貌及内部结构变化，揭示两性离子化合物提高PEDOT:PSS薄膜电导率和表界面性能的作用机理，建立提高薄膜电导率和表界面性能的有效调控方法。考察PEDOT:PSS薄膜表界面电子和空穴的输运特性，探讨PEDOT:PSS纳米复合薄膜影响有机太阳电池器件性能的机理，为低成本高性能的有机太阳电池器件的研发提供良好的科学理论基础。

导电聚合物PEDOT:PSS具有优异的光学/电学性能、高的功函数和易于通过掺杂等方式提高电导率等优点，可作为界面层或透明导电电极应用于有机太阳电池(有机聚合物太阳电池，有机无机杂化钙钛矿太阳电池)。本项目基于纳米复合技术，构筑了具有不同电导率和表界面性能的两性离子化合物/PEDOT:PSS薄膜。研究发现PEDOT:PSS薄膜电导率的提高和表面形貌变化主要机理是两性离子化合物渗透到PEDOT:PSS薄膜内部，促使PEDOT链与PSS链相互分离重构，导电的PEDOT链堆垛形成连续通道。本项目建立了几种提高PEDOT:PSS薄膜电导率和表界面性能的有效调控方法：(1)制备PEDOT:PSS/HPSA双层膜作为ITO替代透明电极应用于有机聚合物太阳电池中，系统研究了PEDOT:PSS薄膜表界面形貌和功函数对电池器件性能的影响;(2)引入两性离子化合物3-环己胺-2-羟基丙磺酸(CAPSO)制备PEDOT:PSS纳米复合薄膜，将其作为空穴传输层其应用于钙钛矿太阳电池中，CAPSO的引入提高了薄膜表面功函数，并使太阳电池器件的能量转换效率提高了约40%。除此以外，我们采用界面分子工程方法，通过插入阴极缓冲层的方式有效地解决溶液法制备钙钛矿太阳电池中，因界面缺陷导致器件性能降低的问题。研究了乙酰丙酮金属盐和肝素钠分子对缺陷钝化和器件衰减的影响，提高了器件效率，并抑制了电滞回线现象和缺陷诱发的电荷复合。本项目在执行过程中，共计发表SCI论文8篇，授权发明专利一项，达到了预期的研究目标。