高效率非富勒烯型全小分子太阳能电池

Non-Fullerene Small-Molecule Organic Solar Cells, owing to the advantages of non-fullerene acceptor which are easier to tune the light absorption and energy level and small molecules are better controlled purity, have been considered as a new topic in the field of organic solar cells. In recent years, the photovoltaic performance of fullerene-free OSCs were improved rapidly and exhibited promising properties for practical applications. However, the efficiencies obtained from fullerene-free Small-Molecule OSCs are still lower than those achieved from the fullerene-based Small-Molecule OSCs. In our preliminary studies, we successfully fabricated the fullerene-free Small-Molecule OSCs with an outstanding efficiencies of 11.24%, which is almost the same as the world record efficiency obtained from fullerene-based Small-Molecule OSCs. In this project, we propose to systematically carry out the studies on the donor materials for the applications in fullerene-free Small-Molecule OSCs. We plan to design and synthesize a few series of new donors small molecules and then investigate the device fabrication methods based on these new materials. Based on the above proposed research plan, we will realize over 14% efficiency infullerene-free Small-Molecule OSCs, which will make great contributions for the OSC research filed.

非富勒烯型全小分子太阳能电池，具有有机小分子材料纯度可控和非富勒烯受体材料光谱能级可调的双重优势，成为有机太阳能电池领域的重要研究课题。近年来，通过有机小分子给体材料分子设计和给受体形貌的调控，我们成功制备了效率达11.24%的溶液可加工非富勒烯型全小分子太阳能电池，是该类太阳能电池的世界最高效率。在本项目中，我们将在前期工作的基础上，围绕“非富勒烯受体各向异性的特征，导致的载流子传输受限和活性层聚集态结构调控困难”这一关键科学问题，研究小分子给体材料设计方法，获得新型的小分子给体材料；调控有机小分子给体-非富勒烯受体的相结构和分子排列，解决制约溶液可加工有机全小分子太阳电池光伏性能提升的瓶颈因素；优化器件的制备加工工艺，将溶液可加工非富勒烯型全小分子太阳能电池效率推进到14%以上。本项目的预期成果将加深对全小分子太阳能电池分子设计和形貌调控的认识，并对有机太阳能电池领域产生重要的推动。

由于非富勒烯型有机全小分子太阳能电池，兼具有机小分子材料纯度可控无合成批次影响，以及非富勒烯受体材料光谱能级可调的双重优势，成为有机太阳能电池领域的重要研究课题。通过本项目的实施，围绕“非富勒烯受体各向异性的特征，使得载流子传输受限和活性层聚集态结构调控困难，导致非富勒烯全小分子光伏器件能量转效率较低”这一关键科学问题。设计与合成一系列针对非富勒烯受体，具有新型大平面扩展二维共轭骨架结构，具有宽带隙和深HOMO能级的给体分子光伏材料。在材料设计中，通过调节分子末端烷基链段，诱导薄膜聚集态下分子取向，发展了调制有机光伏材料分子取向的新方法；同时系统研究了光伏材料结构与器件性能之间的构效关系，调控有机小分子给体-非富勒烯受体的相结构和分子排列，解决制约溶液可加工有机全小分子太阳电池光伏性能提升的瓶颈因素；成功设计构筑出能量转换效率超过15%的二元溶液可加工全小分子太阳电池和能量转换效率超过17%的三元器件，实现了全小分子器件能量转化效率的突破，是领域内引发“溶液可加工有机小分子太阳电池”研究热点的工作。