End-cap Group Engineering of a Small Molecule Non-Fullerene Acceptor: The Influence of Benzothiophene Dioxide
End-cap Group Engineering of a Small Molecule Non-Fullerene Acceptor: The Influence of Benzothiophene Dioxide
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DOI：
10.1021/acsaem.8b01576
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发表时间：
2018-12-01
影响因子：
6.4
通讯作者：
Rupar, Paul A.
中科院分区：
文献类型：
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作者：
Cao, Hongda;Bauer, Nicole;Rupar, Paul A.
在这项研究中，选择了一个含磺基的端盖部分，苯并噻吩二氧化，来制备非富勒烯受体ITBC。ITBC具有受体-供体-受体（A-D-A）结构，其富电子核心部分为吲哚二噻吩[3,2-b]-噻吩（IDTT）。强吸电子的磺酰受体单元使其紫外-可见吸收扩展到近红外区域，具有较低的前沿分子轨道能级（LUMO/HOMO: -4.13 eV/-5.61 eV）和窄带隙（1.48 eV）。这些值与被广泛研究的小分子受体2-（3-氧-2,3-二氢吲哚-1-酰基）丙二腈端封的吲哚二硫烯[3,2-b]噻吩（ITIC）相比具有优势。以氟化共轭聚合物FTAZ为供体，ITBC为受体制备有机太阳能电池，功率转换效率为4.17%。这些结果表明，二氧化苯并噻吩是一种新型的ITBC吸电子端盖单元，可以作为有机太阳能电池的电子受体。
In this study, a sulfonyl-containing end-capping moiety, benzothiophene dioxide, was selected to prepare the nonfullerene acceptor ITBC. ITBC has an acceptor-donor-acceptor (A-D-A) structure, with indacenodithieno[3,2-b]-thiophene (IDTT) as the electron-rich core moiety. The strong electron-withdrawing sulfonyl acceptor units leads to extended UV-vis absorption into the near-IR region and relatively low frontier molecular orbital energy levels (LUMO/HOMO: -4.13 eV/-5.61 eV) with a narrow bandgap of 1.48 eV. These values compare favorably to the well-studied small molecule acceptor 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile end-capped indacenodithieno[3,2-b]thiophene (ITIC). A power conversion efficiency of 4.17% was achieved by fabricating organic solar cells with the fluorinated conjugated polymer FTAZ as the donor and ITBC as the acceptor. These results indicate that benzothiophene dioxide is a novel electron-withdrawing end-capping unit for ITBC, and can be used as an electron acceptor for organic solar cells.