新型非共轭小分子界面材料及其高效聚合物太阳能电池研究

Interfacial material is one of the key techniques to realize high efficiency polymer solar cells (PSC). It is beneficial for charge transmission and collection, optimizing the absorption spectrum of active layer and adjusting its optical field distributions, thus to improve the device stability and performance. By now, the main interfacial materials are based on vacuum deposited inorganic salts,or complicated synthesized organic congjugated molecules. Easily purified, solution processable and low-cost organic non-conjugated small molecule interfacial materials are seldom reported. . In this proposal, a novel series of small molecules non-conjugated zwitterions used as interface materials with excellent charge transport and extraction characteristics are designed and synthesized in the proposal. By selecting the appropriate heteroatom and double/multiply branch structure to regulate the HOMO and LUMO energy levels of molecules, and using intramolecular double or multiple of ion pairs, we wish to achieve high photoelectric conversion efficiency of polymer solar cells. On the other hand, the ultrafast pump-push photocurrent technique and theoretical simulation were introduced to explore the photophysical process of transfer and extraction of carriers in these zwitterions. Moreover, the molecular stuctures and performance of the devices will be investigated systematically in the proposal.The object is to understand the rules of small molecules non-conjugated zwitterions for high-efficiency polymer solar cells, and then develop single layer PSCs with high PCE 10-12%.

界面修饰材料是实现高效率聚合物太阳能电池(PSC)的关键技术之一。它有利于电荷的选择性传输和收集、优化吸收谱和调节光场分布、保护活性层的稳定。目前界面材料主要是需要蒸镀的无机盐、或复杂合成才能制备的有机共轭分子，而易于纯化、可湿法加工的低成本有机非共轭小分子界面材料鲜见报道。本项目首次提出拟设计、合成系列具有优异电荷传导与提取特性的双亲离子型小分子非共轭界面材料，通过选择适当的杂原子和双/多枝化结构来调控分子的HOMO及LUMO能级，利用分子内的双或多个双亲离子对，实现高光电转换效率的聚合物太阳能电池；另一方面，应用超快泵浦光电流技术和理论模拟，探究小分子非共轭界面材料中载流子的传输和提取过程中的光物理过程，总结小分子非共轭界面材料作为高效率聚合物太阳能电池界面层的结构设计规律，研发效率10-12%的单结聚合物太阳能电池。

界面修饰材料是实现高效率聚合物太阳能电池(PSC)的关键技术之一。它有利于电荷的选择性传输和收集、优化吸收谱和调节光场分布、保护活性层的稳定。目前界面材料主要是需要蒸镀的无机盐、或复杂合成才能制备的有机共轭分子，而易于纯化、可湿法加工的低成本有机非共轭小分子界面材料鲜见报道。申请人基本按照预定的研究计划开展了非共轭界面材料的合成及其有机太阳能电池的研究，合成了12 种以上磺酸基界面修饰材料，通过研究相关的薄膜形态、 极性溶剂处理、 界面优化和器件工艺，实现了制备光电转换效率超过15%的单结聚合物太阳能电池的目标。在 Adv. Mater、Angew. Chem、J Mater Chem A、ACS Appl. Mater. Interfaces、Chem. Mater. 等期刊上发表标准本基金号（ No.21574144） SCI 论文45篇，申请专利6项。在本基金的支持下，培养博士后3人，博士生4人，硕士生7人。