Rationally regulating the terminal unit and copolymerization spacer of polymerized small-molecule acceptors for all-polymer solar cells with high open-circuit voltage over 1.10 V
Rationally regulating the terminal unit and copolymerization spacer of polymerized small-molecule acceptors for all-polymer solar cells with high open-circuit voltage over 1.10 V
复制标题
合理调控开路电压1.10 V以上全聚合物太阳能电池聚合小分子受体末端单元和共聚间隔基
DOI：
10.1039/d2ta03647a
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发表时间：
2022-07-06
影响因子：
11.9
通讯作者：
Huang, Fei
中科院分区：
文献类型：
--
作者：
Jia, Tao;Zhang, Jiabin;Huang, Fei
最近，聚合小分子受体 (PSMA) 的巨大进步使全聚合物太阳能电池 (all-PSC) 的功率转换效率 (PCE) 突破了 17% 的里程碑。然而，重要的研究工作主要致力于通过改变结构单元和烷基侧链来设计窄带隙 PSMA。在这项工作中，我们报告了通过结合新型无异构化末端单元 5-溴-4,7-二氟-1H-茚-1,3(2H)-二酮 (FFOBr) 设计了具有宽带隙的新型 PSMA。所得的 PSMA 表现出超过 10(5) M-1 cm(-1) 的高摩尔吸收系数、约 1.65 eV 的相对较宽的带隙以及高于 -3.70 eV 的高位最低占据分子轨道 (LUMO) 能级。当与聚合物供体 JD40 匹配时，两种聚合物受体由于其较高的 LUMO 能级，可以实现具有超过 1.10 V 开路电压 (V-OC) 的高效全 PSC。此外，通过筛选共聚间隔物，PFFO-Th基共混膜表现出良好的形貌、更有序的结晶、改善的电荷传输和减少的复合损失，这些共同有助于提高短路电流密度和填充因子，从而实现10.8%的高PCE。该值是文献报道中 V-OC 超过 1.10 V 的基于 PSMA 的全聚合物太阳能电池的最佳值之一。我们的工作表明，终端单元和连接操作是开发具有可控带隙的高性能 PSMA 的有效策略。
Recently, great advances in polymerized small molecular acceptors (PSMAs) have boosted the power conversion efficiencies (PCEs) of all-polymer solar cells (all-PSCs) over the 17% milestone. However, significant research efforts have been mainly dedicated to designing narrow bandgap PSMAs by altering the building block and alkyl side chain. In this work, we report the design of novel PSMAs with wide bandgaps by incorporating a novel terminal unit without isomerization, 5-bromo-4,7-difluoro-1H-indene-1,3(2H)-dione (FFOBr). The resulting PSMAs exhibit high molar absorption coefficient over 10(5) M-1 cm(-1), relatively wide bandgaps about 1.65 eV as well as high-lying lowest occupied molecular orbital (LUMO) energy levels of above -3.70 eV. When matching with the polymer donor JD40, both polymer acceptors can enable efficient all-PSCs with over 1.10 V open-circuit voltage (V-OC) due to their high-lying LUMO energy level. Moreover, with a screened copolymerization spacer, the PFFO-Th-based blend film exhibits favorable morphology, more ordered crystallization, improved charge transport, and reduced recombination losses, which together contribute to the higher short-circuit current density and fill factor and thereby a high PCE of 10.8%. This value is one of the best with regard to PSMA-based all-polymer solar cells with V-OC over 1.10 V in the reported literature. Our work shows that the terminal unit and linkage manipulation are effective strategies to develop high-performance PSMAs with controllable bandgaps.