Haptacyclic Carbazole-Based Ladder-Type Nonfullerene Acceptor with Side-Chain Optimization for Efficient Organic Photovoltaics
Haptacyclic Carbazole-Based Ladder-Type Nonfullerene Acceptor with Side-Chain Optimization for Efficient Organic Photovoltaics
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DOI：
10.1021/acsami.7b12612
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发表时间：
2017-12-06
影响因子：
9.5
通讯作者：
Hsu, Chain-Shu
中科院分区：
文献类型：
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作者：
Hsiao, Yu-Tang;Li, Chia-Hua;Hsu, Chain-Shu
在这项研究中，基于七环咔唑的二噻吩环五氮杂环（DTCC）梯型结构被甲酰基化，与两个1，1-二氰亚甲基-3-茚满酮（IC）部分偶联，形成新的非富勒烯受体DTCCIC-C17，其中在嵌入的咔唑的氮原子上有一个庞大的支化1-辛基壬基侧链，在sp（3）-碳桥上有四个4-辛基苯基。DTCC核的刚性共面主链提供了宽的光吸收窗口和较高的LUMO能级，而庞大的侧链减少了分子间的相互作用，使DTCCIC-C17具有优异的溶液加工性。将作为受体的DTCCIC-C17与作为活性层中的供体的中等带隙聚合物聚[（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'-二-2-噻吩基-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）组合，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。为了获得更好的器件稳定性，制造了具有倒置配置（ITO/ZnO/有源层/MoO 3/Ag）而不使用水性聚（3，4-乙撑二氧噻吩）聚苯乙烯磺酸盐层的器件。当二碘辛烷处理的PBDB-T：DTCCIC-C17活性层在50摄氏度下热退火10分钟时，器件实现了9.48%的最高效率，具有0.98 V的高V-oc、14.27 mA cm（-2）的J（sc）和0.68的FF。
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(3)-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-y1)-benzo[1,2-b:4,5-bldithiophene))-alt-(5,5-(1',3'-di-2-thieny1-5',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/MoO3/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 degrees C for 10 min, the device achieved the highest efficiency of 9.48% with a high V-oc of 0.98 V, a J(sc) of 14.27 mA cm(-2), and an FF of 0.68.