Department of Materials Science and Engineering, College of Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University , Beijing 100871, China.
Fujian Key Laboratory of Polymer Materials, College of Materials Science and Engineering, Fujian Normal University , Fuzhou 350007, China.
J Am Chem Soc. 2017 Jan 25;139(3):1336-1343. doi: 10.1021/jacs.6b12755. Epub 2017 Jan 13.
We design and synthesize four fused-ring electron acceptors based on 6,6,12,12-tetrakis(4-hexylphenyl)-indacenobis(dithieno[3,2-b;2',3'-d]thiophene) as the electron-rich unit and 1,1-dicyanomethylene-3-indanones with 0-2 fluorine substituents as the electron-deficient units. These four molecules exhibit broad (550-850 nm) and strong absorption with high extinction coefficients of (2.1-2.5) × 10 M cm. Fluorine substitution downshifts the LUMO energy level, red-shifts the absorption spectrum, and enhances electron mobility. The polymer solar cells based on the fluorinated electron acceptors exhibit power conversion efficiencies as high as 11.5%, much higher than that of their nonfluorinated counterpart (7.7%). We investigate the effects of the fluorine atom number and position on electronic properties, charge transport, film morphology, and photovoltaic properties.
我们设计并合成了四个基于 6,6,12,12-四(4-己基苯基)茚并二噻吩[3,2-b;2',3'-d]噻吩作为富电子单元和 1,1-二氰基-3-茚满酮的稠合环电子受体，后者带有 0-2 个氟取代基作为缺电子单元。这四个分子表现出宽（550-850nm）且强吸收，具有高消光系数（2.1-2.5）×10 M cm。氟取代降低了 LUMO 能级，红移了吸收光谱，并增强了电子迁移率。基于氟化电子受体的聚合物太阳能电池的功率转换效率高达 11.5%，远高于其非氟化对应物（7.7%）。我们研究了氟原子数量和位置对电子性质、电荷输运、薄膜形貌和光伏性能的影响。
