School of Materials and Chemical Engineering, Zhongyuan University of Technology, Zhengzhou 451191, China.
Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450003, China.
Int J Mol Sci. 2022 Sep 3;23(17):10079. doi: 10.3390/ijms231710079.
We designed and synthesized an asymmetric non-fullerene small molecule acceptor (NF-SMA) IDT-TNIC with an A-D-π-A structure, based on an indacenodithiophene (IDT) central core, with a unidirectional non-fused alkylthio-thiophene (T) π-bridge, and 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene)malononitrile (NIC) extended terminal groups. IDT-TNIC molecules still maintain a good coplanar structure, which benefits from the non-covalent conformational locks (NCL) between O···S and S···S. The asymmetric structure increases the molecular dipole moment, and the extended terminal group broadens the absorption of the material, resulting in an excellent photovoltaic performance of IDT-TNIC. The photovoltaic device, based on PBDB-T:IDT-TNIC, exhibits an energetic PCE of 11.32% with a high of 0.87 V, high of 19.85 mA cm, and a low energy loss of 0.57 eV. More importantly, IDT-TNICs with asymmetric structures show a superior property compared to symmetric IDT-Ns. The results demonstrate that it is an effectual strategy to enhance the properties of asymmetric A-D-π-A-based NF-SMAs with non-fused NCL π-bridges and extended terminal groups.
我们设计并合成了一种具有 A-D-π-A 结构的不对称非富勒烯小分子受体（NF-SMA）IDT-TNIC，它基于茚并二噻吩（IDT）中心核，具有单向非稠合的烷基硫代噻吩（T）π-桥，以及 2-（3-氧代-2,3-二氢-1H-环戊[b]萘-1-亚基）丙二腈（NIC）扩展端基。IDT-TNIC 分子仍然保持良好的共面结构，这得益于 O···S 和 S···S 之间的非共价构象锁定（NCL）。不对称结构增加了分子偶极矩，扩展的端基拓宽了材料的吸收，从而使 IDT-TNIC 具有优异的光伏性能。基于 PBDB-T:IDT-TNIC 的光伏器件表现出 11.32%的能量 PCE，开路电压为 0.87 V，短路电流为 19.85 mA cm，能量损耗低至 0.57 eV。更重要的是，具有不对称结构的 IDT-TNIC 表现出比对称的 IDT-Ns 更好的性能。结果表明，采用非稠合 NCL π-桥和扩展端基来增强不对称 A-D-π-A 基 NF-SMA 的性能是一种有效的策略。
