基于高荧光量子产率低非辐射能量损失的非富勒烯受体材料在高效率有机太阳电池中的研究

For high-efficiency solar cells (PCE>20%) based on crystalline silicon, organic inorganic hybrid perovskite, gallium arsenide, the energy loss is only at 0.4eV-0.55 eV. Compared with its counterpart, the energy loss of organic solar cell is about 0.7ev-1.0ev, therefore, the high energy loss of organic solar cells is one of the key factors that limit the further improvement of the PCE of organic solar cells. There are two ways to reduce the energy loss of organic solar cells, one is increasing the charge transfer state energy in donor-acceptor system (which can be achieved by reducing the LUMO offset between the donor and acceptor), anther is reducing the non-radiative energy loss of organic solar cells (which can be achieved by improving the luminous efficiency of the solar cell). In this proposal, my team will synthesize high fluorescence luminescence characteristic non-fullerenes receptor materials to reduce the non-radiative energy loss and study the energy loss mechanism in the prepared organic solar cells based on synthesized non-fullerene materials. The main research result will provide guidance for the synthesis of non-fullerenes receptors and the fabrication of organic solar cells with low energy loss.

能量转换效率超20%的高率效晶硅、有机无机杂化钙钛矿和砷化镓等太阳电池能量损失仅为0.4eV-0.55eV，而有机太阳电池器件的能量损失在0.7eV-1.0eV之间，较高的能量损失是限制有机太阳电池效率进一步提高的关键性影响因素之一。降低器件能量损失的途径除了通过提高给受体之间的电荷转移态能量外（可通过降低给受体之间的LUMO差值实现），另一个手段是降低器件的非辐射能量损失（可通过提高器件的发光效率来实现）；本项目通过合成具有高荧光发光特性的非富勒烯受体材料，通过提高器件的发光性能来降低器件的非辐射能量损失并研究制备器件中的能量损失机理，为以后合成具有低能量损失的非富勒烯受体和制备低能量损失高效率的非富勒烯太阳电池提供相关的指导。

设计开发了一类基于二噻吩并吡咯为母核的非富勒烯小分子受体材料，通过改变IDTP-4F中二噻吩并吡咯母核中噻吩单元的位置，采用异构化策略，开发了ThPy5和ThPy6两个异构体。其次，通过调控重结晶溶剂纯化得到了两个端基异构体BrIC-5 和 BrIC-6，并进一步选取合适的稠环单元苯并噻二唑二并吡咯二并并二噻吩（BTP）制备了两个无异构的具有近红外强吸收的非富勒烯受体小分子BTPIC-2Br-5和BTPIC-2Br-6，以及相应的聚合物受体材料PA-5和PA-6。探究了材料结构与光伏性能之间的构效关系及载流子的动力学过程。再次，通过将不同比例的三氟甲基酯基团取代噻吩(TEST)单元引入经典的聚合物给体PBDB-TF中，合成了4种新型聚合物给体材料（材料代号：FF0.2, FF0.5, FF0.8,和 FF1），研究了不同比例的三氟甲基酯基团取代噻吩(TEST)单元引入经典的聚合物给体PBDB-TF对给体材料的能级、吸收、载流子的迁移率、所制备的共混薄膜形貌和器件光伏性能的影响。最后，本项目通过合成水醇溶的小分子受体材料用于制备阴极界面修饰层，并研究了其相关的工作机理。