Department of Materials Science and Engineering, The Johns Hopkins University, 102 Maryland Hall, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
J Am Chem Soc. 2010 Apr 21;132(15):5394-404. doi: 10.1021/ja909111p.
Four ladder-type oligo-p-phenylene containing donor-acceptor copolymers were designed, synthesized, and characterized. The ladder-type oligo-p-phenylene was used as an electron donor unit in these copolymers to provide a deeper highest occupied molecular orbital (HOMO) level for obtaining polymer solar cells with a higher open-circuit voltage, while 4,7-dithien-2-yl-2,1,3-benzothiadiazole or 5,8-dithien-2-yl-2,3-diphenylquinoxaline was chosen as an electron acceptor unit to tune the electronic band gaps of the polymers for a better light harvesting ability. These copolymers exhibit field-effect mobilities as high as 0.011 cm(2)/(V s). Compared to fluorene containing copolymers with the same acceptor unit, these ladder-type oligo-p-phenylene containing copolymers have enhanced and bathochromically shifted absorption bands and much better solubility in organic solvents. Photovoltaic applications of these polymers as light-harvesting and hole-conducting materials are investigated in conjunction with [6,6]-phenyl-C61-butyric acid methyl ester (PC(61)BM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC(71)BM). Without extensive optimization work, a power conversion efficiency (PCE) of 3.7% and a high open-circuit voltage of 1.06 V are obtained under simulated solar light AM 1.5 G (100 mW/cm(2)) from a solar cell with an active layer containing 20 wt % ladder-type tetra-p-phenylene containing copolymer (P3FTBT6) and 80 wt % PC(61)BM. Moreover, a high PCE of 4.5% was also achieved from a solar cell with an active layer containing 20 wt % P3FTBT6 and 80 wt % PC(71)BM.
设计、合成并表征了四种含梯型寡聚对苯撑的给体-受体共聚物。在这些共聚物中，梯型寡聚对苯撑被用作电子给体单元，以提供更深的最高占据分子轨道（HOMO）能级，从而获得具有更高开路电压的聚合物太阳能电池，而 4,7-二噻吩-2-基-2,1,3-苯并噻二唑或 5,8-二噻吩-2-基-2,3-二苯基喹喔啉则被选为电子受体单元，以调整聚合物的电子能带隙，从而提高其对光的捕获能力。这些共聚物的场效应迁移率高达 0.011 cm²/（V s）。与具有相同受体单元的含芴共聚物相比，这些含梯型寡聚对苯撑的共聚物具有增强且红移的吸收带，并且在有机溶剂中的溶解度更好。这些聚合物作为光捕获和空穴传输材料的光伏应用与[6,6]-苯基-C61-丁酸甲酯（PC（61）BM）或[6,6]-苯基-C71-丁酸甲酯（PC（71）BM）一起进行了研究。在模拟太阳光 AM 1.5 G（100 mW/cm²）下，无需进行广泛的优化工作，一个含有 20wt%梯型四聚对苯撑的共聚物（P3FTBT6）和 80wt%PC（61）BM 的活性层的太阳能电池可获得 3.7%的功率转换效率（PCE）和 1.06 V 的高开路电压。此外，一个含有 20wt%P3FTBT6 和 80wt%PC（71）BM 的活性层的太阳能电池也可获得 4.5%的高 PCE。
