基于3-氰基噻吩的不对称非稠环电子受体材料的设计合成及其光伏性能研究  

Design,Synthesis,and Photovoltaic Performance of Asymmetric Non-fused Ring Electron Acceptors Based on 3-Cyanothiophene

作　　者：丁学妍 陈天一 李水兴 施敏敏[1] 陈红征[1,2] Xue-yan Ding;Tian-yi Chen;Shui-xing Li;Min-min Shi;Hong-zheng Chen(State Key Laboratory of Silicon and Advanced Semiconductor,Department of Polymer Science and Engineering,Zhejiang University,Hangzhou 310058;Institute of Information and Functional Materials Research,ZJU-Hangzhou Global Scientific and Technological Innovation Center,Hangzhou 311200)

机构地区：[1]浙江大学硅及先进半导体材料全国重点实验室高分子科学与工程学系,杭州310058 [2]浙江大学杭州国际科创中心信息与功能材料研究院,杭州311200

出　　处：《高分子学报》2025年第4期515-526,共12页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号52273199,52321165650,52127806);中央高校基本科研基金(基金号226-2024-00005,226-2024-00056)资助.

摘　　要：建立晶体结构、分子堆积和光伏性能之间的内在联系,对于推动非稠环电子受体材料的发展具有重要意义,而偶极矩是调控分子堆积方式的手段之一.为此,本研究基于强偶极的3-氰基噻吩构筑单元,开发了一系列不对称非稠环电子受体(X4、X5和X6),并深入研究了末端基团结构的差异对分子光电特性及有机太阳能电池性能的影响.氰基的强吸电子性,有效削弱了噻吩的给电子效应,从而使受体保持较深的HOMO能级,与给体材料PM6实现了良好的能级匹配.单晶结构解析显示,分子中心的强偶极驱使分子采取面对面的二聚体排布,而分子末端的差异化改变了二聚体之间的堆叠方式,其中氟代X4的二聚体之间以J聚集的形式排列,氯代X5的二聚体之间以H聚集和J聚集共存的形式排列.最终,基于具有更大共轭末端基团的X6制备的器件实现了19.90 mA·cm^(−2)的短路电流密度(short-circuit current density,JSC)、72.38%的填充因子(fill factor,FF)和12.05%的能量转化效率(power conversion efficiency,PCE),优于X4(11.81%)和X5(11.87%)的器件效率.Establishing the intrinsic relationship among crystal structure,molecular packing,and photovoltaic performance is crucial for advancing non-fused ring electron acceptor(NFREA)materials,while dipole moment serves as one of the key factors in regulating molecular packing.In this work,based on the large dipole 3-cyanothiophene building block,a series of asymmetric NFREAs(X4,X5,and X6)were developed,for which the impacts of varied terminal groups on the molecular optoelectronic properties and photovoltaic performance were systematically investigated.The strong electron-withdrawing ability of the cyano-group significantly weakens the electron-donating effect of the thiophene unit,resulting in relatively deep HOMO levels for the acceptors,thus enabling favorable energy level alignment with the donor PM6.Single-crystal analysis revealed that the strong dipole moment at the molecular core drives the dimer formed in face-to-face arrangement,while variations in terminal groups alter the stacking arrangements between dimers.Specifically,the fluorinated X4 adopts Jaggregation packing between dimers,while the chlorinated X5 tends to the co-existence of H-aggregation and Jaggregation packing between dimers.Ultimately,organic solar cells based on X6,which bears larger conjugated terminal groups,achieved a short-circuit current density(JSC)of 19.90 mA·cm^(−2),a fill factor(FF)of 72.38%,and a power conversion efficiency(PCE)of 12.05%,outperforming those based on X4(11.81%)and X5(11.87%).

关 键 词：有机太阳能电池 不对称 非稠环受体 3-氰基噻吩 晶体结构 

分 类 号：O62[理学—有机化学] TM914.4[理学—化学]