Solvent‐Induced Polymorphism in Non‐Fullerene‐Based Organic Solar Cells
Solvent‐Induced Polymorphism in Non‐Fullerene‐Based Organic Solar Cells
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非富勒烯有机太阳能电池中溶剂诱导的多晶型现象
DOI：
10.1002/solr.202200819
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发表时间：
2022
期刊：
影响因子：
7.9
通讯作者：
Ma, Wei
中科院分区：
文献类型：
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作者：
Xin, Jingming;Zhao, Heng;Xue, Jingwei;Seibt, Susanne;Collins, Brian A.;Ma, Wei
由于非富勒烯受体（NFA）的上级聚集和堆积性质，有机光致发光材料在功率转换效率方面取得了突破。溶液加工和各种处理往往会形成最先进的NFA的独特包装图案。本文揭示了由氯仿（CF）和氯苯（CB）制备的3，9-双（2-亚甲基-（3-（1，1-二氰基亚甲基）-茚满酮））-5，5，1,1，1,1-四（4-己基苯基）-二噻吩并[2，3-d：2′，3 ′-d′]-s-引达省并[1，2-B：5，6-B′]二硫吩）（ITIC）的溶剂诱导多晶型。ITIC的堆积基序表现出来自CF诱导的密集的π-π堆积，这表现出红移吸收和可逆的高温结晶和熔融。同时，CB溶液中可以形成较强的片层堆积和π-π堆积，低温结晶和熔融不稳定。结合原位吸收光谱和相互作用计算，发现ITIC在CF溶液中较强的预聚集是形成不同于CB溶液中的堆积基序的主要原因。在PBDB-T：ITIC共混物中保留了包装和热力学特征，尽管良好的可溶解性削弱了特征。得益于多晶型结构，CB处理的器件表现出更好的性能，但热稳定性较差。该研究表明溶剂诱导对于操纵和优化有机太阳能电池器件的形貌具有重要作用。
Organic photovoltaics have achieved breakthroughs in power conversion efficiency due to the superior aggregation and packing nature of non‐fullerene acceptors (NFAs). Solution processing and various treatments would tend to form distinct packing motifs for state‐of‐the‐art NFAs. Herein, the solvent‐induced polymorphism for 3,9‐bis(2‐methylene‐(3‐(1,1‐dicyanomethylene)‐indanone))‐5,5,11,11‐tetrakis(4‐hexylphenyl)‐dithieno[2,3‐d:2′,3′‐d′]‐s‐indaceno[1,2‐b:5,6‐b′]dithiophne) (ITIC) prepared by chloroform (CF) and chlorobenzene (CB) is revealed. The packing motif of ITIC exhibits dense π–π stacking from CF induction, which presents red‐shifted absorption and reversible high‐temperature crystallization and melting. Meanwhile, strong lamellar stacking and π–π stacking can be formed in the CB solution with unstable low‐temperature crystallization and melting. Combining in situ absorption spectra and interaction calculation, the stronger preaggregation of ITIC in the CF solution was found to be the main reason for forming a different packing motif from in the CB solution. The packing and thermodynamic features are retained in the PBDB‐T:ITIC blends, though good miscibility weakens characteristic features. Benefiting from the polymorph structure, CB‐processed devices denote more favorable performance but less thermal stability. This research indicates the significant effect of solvent induction for manipulating and optimizing the morphology of organic solar cell devices.