Zhang Youdi, Shao Yiming, Wei Zhouyin, Zhang Lifu, Hu Yu, Chen Lie, Chen Shanshan, Yuan Zhongyi, Chen Yiwang
College of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031, China.
Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang 330031, China.
ACS Appl Mater Interfaces. 2020 May 6;12(18):20741-20749. doi: 10.1021/acsami.0c02862. Epub 2020 Apr 22.
Random conjugated terpolymers (RCTs) not only promote great comprehension and realization for the state-of-the-art highly effective non-fullerene organic solar cells (OSCs) but also offer a simple and practical synthetic strategy. However, the photovoltaic properties of RCTs yet lagged behind that of the donor-acceptor (D-A) alternating copolymer, especially in additive-free devices. Hence, we developed two feasible "double-acceptor-type" random conjugated terpolymers, PBDB-TAZ20 and PBDB-TAZ40. The additive-free OSCs based on PBDB-TAZ20:ITIC and PBDB-TAZ40:ITIC exhibit decent efficiencies of 12.34 and 11.27%, respectively, which both surpass the PBDB-T:ITIC-based device. For RCTs, the reasonably weakened crystallinity and the reduced phase separation degree are demonstrated to help in improving charge transport, reducing bimolecular recombination, and thus enhancing the photovoltaic performance of additive-free OSCs. The results imply that adding a third moiety into the D-A polymer donors provides a simple but efficient synthetic approach for high-performance OSCs.
随机共轭三元共聚物（RCTs）不仅极大地促进了人们对当前最先进的高效非富勒烯有机太阳能电池（OSCs）的理解和认识，还提供了一种简单实用的合成策略。然而，RCTs的光伏性能仍落后于供体-受体（D-A）交替共聚物，尤其是在无添加剂器件中。因此，我们开发了两种可行的“双受体型”随机共轭三元共聚物，PBDB-TAZ20和PBDB-TAZ40。基于PBDB-TAZ20:ITIC和PBDB-TAZ40:ITIC的无添加剂OSCs分别展现出12.34%和11.27%的可观效率，均超过了基于PBDB-T:ITIC的器件。对于RCTs，合理减弱的结晶度和降低的相分离程度被证明有助于改善电荷传输、减少双分子复合，从而提高无添加剂OSCs的光伏性能。结果表明，在D-A聚合物供体中引入第三种成分，为高性能OSCs提供了一种简单而有效的合成方法。
