Department of Applied Chemistry, National Chiao Tung University , 1001 University Road, Hsinchu 30010, Taiwan.
RIKEN Center for Emergent Matter Science (CEMS) , 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
ACS Appl Mater Interfaces. 2017 Dec 6;9(48):42035-42042. doi: 10.1021/acsami.7b12612. Epub 2017 Nov 22.
In this research, a haptacyclic carbazole-based dithienocyclopentacarbazole (DTCC) ladder-type structure was formylated to couple with two 1,1-dicyanomethylene-3-indanone (IC) moieties, forming a new nonfullerene acceptor DTCCIC-C17 using a bulky branched 1-octylnonayl side chain at the nitrogen of the embedded carbazole and four 4-octylphenyl groups at the sp-carbon bridges. The rigid and coplanar main-chain backbone of the DTCC core provides a broad light-absorbing window and a higher-lying LUMO energy level, whereas the bulky flanked side chains reduce intermolecular interactions, making DTCCIC-C17 amorphous with excellent solution processability. The DTCCIC-C17 as an acceptor is combined with a medium band gap polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))] (PBDB-T) as the donor in the active layer to obtain suitable highest occupied molecular orbital/lowest unoccupied molecular orbital energy alignments and complimentary absorption. The devices with an inverted configuration (ITO/ZnO/active layer/MoO/Ag) without using an aqueous poly(3,4-ethylenedioxythiophene) polystyrene sulfonate layer were fabricated for better device stability. When the diiodooctane-treated PBDB-T:DTCCIC-C17 active layer was thermally annealed at 50 °C for 10 min, the device achieved the highest efficiency of 9.48% with a high V of 0.98 V, a J of 14.27 mA cm, and an FF of 0.68.
在这项研究中，采用甲酰化方法将基于稠合环咔唑的二噻吩并环戊并咔唑（DTCC）梯形结构与两个 1,1-二氰基亚甲基-3-茚酮（IC）部分连接，形成一种新的非富勒烯受体 DTCCIC-C17，其中在嵌入咔唑的氮上带有庞大的支化的 1-辛基壬基侧链，并且在 sp-碳桥处带有四个 4-辛基苯基。DTCC 核心的刚性和共面主链骨架提供了更宽的光吸收窗口和更高的 LUMO 能级，而庞大的侧链减少了分子间相互作用，使 DTCCIC-C17 呈无定形状态，具有优异的溶液加工性能。作为受体的 DTCCIC-C17 与具有中等带隙的聚合物聚[(2,6-(4,8-双(5-(2-乙基己基)噻吩-2-基)苯并[1,2-b:4,5-b']二噻吩))--alt-(5,5-(1',3'-二噻吩-5',7'-双(2-乙基己基)苯并[1',2'-c:4',5'-c']二噻吩-4,8-二酮))]（PBDB-T）结合在活性层中作为给体，以获得合适的最高占据分子轨道/最低未占据分子轨道能量排列和互补吸收。使用倒置结构（ITO/ZnO/活性层/MoO/Ag）制造了没有使用水性聚（3,4-亚乙基二氧噻吩）聚苯乙烯磺酸盐层的器件，以提高器件稳定性。当用二碘辛烷处理 PBDB-T:DTCCIC-C17 活性层并在 50°C 下热退火 10 分钟时，器件实现了最高效率 9.48%，开路电压为 0.98 V，电流密度为 14.27 mA cm-2，填充因子为 0.68。
