Su Mingbin, Lin Man, Mo Songmin, Chen Jinming, Shen Xiangyu, Xiao Yonghong, Wang Meijiang, Gao Jinping, Dang Li, Huang Xiao-Chun, He Feng, Wu Qinghe
Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong, Shantou University, Shantou 515063, Guangdong, China.
Department of Chemistry, Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
ACS Appl Mater Interfaces. 2023 Aug 9;15(31):37371-37380. doi: 10.1021/acsami.3c05668. Epub 2023 Jul 29.
Morphology instability holds the major responsibility for efficiency degradation of organic solar cells (OSCs). However, how to develop polymer donors simultaneously with high efficiency and excellent morphology stability remains challenging. Herein, we reported naphtho[2,1-b:3,4-b']dithiophene-5,6-imide (NDTI)-based new polymers PNDT1 and PNDT2. The alkyl chain engineering leads to high crystallinity, high hole mobility (>10 cm V S), and nanofibrous film morphology, which enable PNDT2 to exhibit an efficiency of 18.13% and a remarkable FF value of 0.80. Moreover, the NDTIs have short π-π stacking and abundant short interactions, and their polymers exhibit superior morphological stability. Therefore, the PNDT2-based OSCs exhibit much better device stability than that of PNDT1, PAB-α, and benchmark polymers PM6 and D18. This work suggests the great importance of the large conjugated backbone of the monomer and alkyl chain engineering to develop high-performance and morphology-stable polymers for OSCs.
形态不稳定性是导致有机太阳能电池（OSC）效率下降的主要原因。然而，如何开发同时具有高效率和优异形态稳定性的聚合物给体仍然具有挑战性。在此，我们报道了基于萘并[2,1-b:3,4-b']二噻吩-5,6-二酰亚胺（NDTI）的新型聚合物PNDT1和PNDT2。烷基链工程导致了高结晶度、高空穴迁移率（>10 cm² V⁻¹ s⁻¹）和纳米纤维薄膜形态，这使得PNDT2表现出18.13%的效率和0.80的显著填充因子值。此外，NDTIs具有短的π-π堆积和丰富的短程相互作用，它们的聚合物表现出优异的形态稳定性。因此，基于PNDT2的OSC比PNDT1、PAB-α和基准聚合物PM6和D18具有更好的器件稳定性。这项工作表明了单体的大共轭主链和烷基链工程对于开发用于OSC的高性能和形态稳定聚合物的重要性。
