【作者】 李水兴； 鄢杰林； 李昌治； 刘峰； 施敏敏； 陈红征； Thomas P.Russell；

【Author】 Shuixing Li;Jielin Yan;Chang-Zhi Li;Feng Liu;Minmin Shi;Hongzheng Chen;Thomas P.Russell;MOE Key Laboratory of Macromolecular Synthesis and Functionalization,State Key Laboratory of Silicon Materials,Department of Polymer Science and Engineering,Zhejiang University;Materials Sciences Division,Lawrence Berkeley National Laboratory;Department of Physics and Astronomy,Shanghai Jiao Tong University;Department of Polymer Science and Engineering,University of Massachusetts;

【机构】 浙江大学高分子科学与工程学系； 美国劳伦斯伯克利国家实验室； 上海交通大学天文物理系； 美国马萨诸塞州立大学高分子科学与工程系；

【摘要】 高效的电子受体材料应当具有低能级、高迁移率等特点,非富勒烯受体材料还能表现出更好的吸收。低能级有利于激子的分离,高迁移率有利于载流子的传输,而更好的吸收可以捕获更多的光子以便产生更大的电流。基于这些设计原则,我们设计并合成了一种以芴为中心,以吡咯并吡咯二酮（DPP）为臂,以氰基噻吩为末端的线性小分子受体材料,F8-DPPTCN。因为氰基噻吩的吸电子性,F8-DPPTCN具有-3.65 e V的低LUMO能级;因为分子较好的平面性,F8-DPPTCN具有1.66 e V的窄带隙以及近红外的吸收。当F8-DPPTCN作为受体材料,与P3HT共混时,可以表现出2.37%的效率,相应的开路电压、短路电流和填充因子分别为0.97 V、6.25 m A cm^-2和0.39。通过SCLC方法测得,P3HT:F8-DPPTCN共混膜可以表现出10^-3 cm2V^-1 s^-1左右的电子迁移率,这个迁移率接近于PCBM的电子迁移率。GIXD和RSo XS的形貌表征显示,F8-DPPTCN容易形成较大的相分离尺寸,这是由分子较好的平面性导致的,这也是限制器件效率的主要原因之一。更多还原

【Abstract】 As an effective electron acceptor material, it should have a deep lowest unoccupied molecular orbital(LUMO) energy level so that it can split excitons effectively. We design and synthesize a non-fullerene electron acceptor(F8-DPPTCN) based on a fluorine core together with arms of diketopyrrolopyrrole(DPP) having thiophene-2-carbonitrile as the terminal units. The new molecule has a LUMO of-3.65 e V and a narrow bandgap(Eg) of 1.66 e V. As expected, F8-DPPTCN possesses good absorption and high electron mobility. A power conversion efficiency(PCE) of 2.37% is obtained for polymer solar cells with poly(3-hexylthiophene)(P3HT) as the donor and F8-DPPTCN as the acceptor. Structural characterization shows the network structure for P3 HT and F8-DPPTCN blended films with thermal annealing or DIO additive is crucial for cells performance. The changes in the PCE could be correlated with the morphological changes, opening pathways to increase performance further.更多还原