Intense Intramolecular Charge Transfer Endows Cyanated Polymer with Broad Absorption,Intensified Light-Harvesting,Long-Lived Exciton,and Superior Photovoltaic Property  

作　　者：Jinming Chen Huijuan Wang Songmin Mo Hui Chen Xinyu He Mingbin Su Dongyan Li Yonghong Xiao Zhiqi Wang Fanwei Ye Mingde Li Li Dang Xiao-Chun Huang Chang-Zhi Li Feng He Qinghe Wu 

机构地区：[1]Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong,Department of Chemistry,Shantou University,Shantou 515063 [2]Department of Chemistry,Shenzhen Grubbs Institute,Southern University of Science and Technology,Shenzhen 518055 [3]Department of Polymer Science and Engineering,Zhejiang University,Hangzhou 310027 [4]Chemistry and Chemical Engineering Guangdong Laboratory,Shantou 515063 [5]Guangdong Provincial Key Laboratory of Catalysis,Southern University of Science and Technology,Shenzhen 518055

出　　处：《CCS Chemistry》2024年第9期2318-2332,共15页中国化学会会刊（英文）

基　　金：supported by the National Natural Science Foundation of China(grant nos.22179076 and 22225504);the Department of Education of Guangdong Province,China(grant no.2021KCXTD032);the Natural Science Foundation of Guangdong Province,China(grant no.2022A1515011803);the Science and Technology Innovation Fund for College students in Guangdong Province,China(grant no.2020329105600A000003);Guangdong Provincial Key Laboratory of Catalysis,China(grant no.2020B121201002).

摘　　要：The donor–acceptor(D–A)copolymers,which exhibit wide broad absorption and intensified light-harvesting,are highly captivating for applications in solar conversion and optoelectronics.However,designing a polymer structure that can achieve these photophysical properties simultaneously remains a challenge.Herein,we report two novel cyanated units 4-cyanobenzo[1,2-b:6,5-b′:3,4-c″]trithiophene(CBT)and 4,6-dicyanobenzo[1,2-b:6,5-b′:3,4-c″]trithiophene(C2BT)and their corresponding polymers,PCBT and PC2BT.Very interestingly,the PC2BT exhibited a broad absorption band with full width at half maxima(FWHM)of its absorption spectra,almost twice wider than PCBT and benchmark polymers PM6 and D18.Moreover,the PC2BT demonstrated intensified light-harvesting and long-lived exciton.Our in-depth investigation unveiled that the presence of dicyano substitutions induced a strong intramolecular charge transfer(ICT),which,in turn,resulted in the formation of favorable photophysical properties.Therefore,PC2BT-based polymer solar cells(PSCs)exhibited an efficiency of 18.06%,which was a record-setting efficiency for cyanated polymers.This study suggests an efficient strategy for enhancing ICT to design polymers toward favorable photophysical properties and excellent photovoltaic performance.

关 键 词：intramolecular charge transfer broad absorption band dicyanobenzotrithiophene cyanated polymer polymer solar cell 

分 类 号：O63[理学—高分子化学]