厚度不敏感型非富勒烯太阳能电池光伏材料的研究

Organic solar cells (OSCs) have attracted considerable attention due to their potential of light weight, low cost and the capability to fabricate flexible large-area devices through roll-to-roll printing techniques. In recent years, on the basis of developing superior fullerene-free acceptors, fullerene-free-based OSCs have achieved comparable power conversion efficiency (PCE) with that of the fullerene-base devices. In addition to the improvement of PCE, it is of great importance to develop novel materials for making fullerene-free-based OSCs with high tolerance of thickness variation. In this project, we will focus on the design and investigation of the novel materials for active layer, which consist of the polymer donor materials with Benzodithiophene (BDT)-based structure and fullerene-free acceptor materials with A-D-A construction. The materials will be applied into the fabrication of OSC devices to investigate their photovoltaic properties, through which we could improve our understanding the relationship between chemical structures and photovoltaic performance. These research will give us a guideline for achieving photovoltaic materials with both high mobility and high tolerance of the thickness of active layer. The research results are of considerable significance for promoting overall performance of polymer solar cells and practical application.

有机太阳能电池因具备可通过低成本溶液法制备大面积柔性器件的突出优点，已受到世界范围的广泛关注。近年来，非富勒烯型有机太阳能电池的相关研究得到了十分迅速的发展，光伏效率屡获突破。在关注提升光伏效率的前提下，发展光伏性能对活性层厚度和纳米聚集结构不敏感的新型材料体系成为有机太阳能电池产业化的关键问题。本项目围绕当前非富勒烯型有机太阳能电池方向缺乏对活性层厚度不敏感的光伏活性层材料的问题，以苯并二噻吩单元类聚合物电子给体和具有A-D-A结构的电子受体为切入点，开展有机光伏材料设计、制备与相应的器件研究工作，设计并制备兼具高迁移率和纳米尺度相分离结构光伏活性层的新型有机电子给体和受体材料，制备出高效率、厚度不敏感的非富勒烯型有机太阳能电池，这些研究结果将对促进有机光伏产业化的发展具有重要意义。

相比于无机光伏技术，有机太阳能电池在柔性、大面积制备等方面具有显著优势。近年来，新型光活性层材料、器件结构优化工艺以及新型界面层材料的协同发展使有机太阳能电池能量转换效率得到了飞速提升，在此前提下，发展高效率厚膜光伏器件成为解决有机光伏技术产业化的有效手段。本项目以发展可以协同实现高能量转换效率与对膜厚不敏感的光伏材料，并制备高效率厚膜器件为目标，即：以苯并二噻吩为基础单元结构设计并制备了一系列高效率共轭聚合物给体材料，同时，针对A-D-A型非富勒烯受体材料也进行了探索性研究工作，并采用上述光伏活性层材料来制备具有膜厚超过300 nm的有机太阳能电池。在本项目的支持下，我们阶段性地获得了领域内同期最高能量转换效率的结果，并先后在活性层厚度超过300 nm 与1000 nm的器件中得到了14%与12%以上的能量转换效率。这些研究结果对提升有机太阳能电池的光伏性能，以及促进其产业化进程具有重要意义。