Gradual chlorination at different positions of D-π-A copolymers based on benzodithiophene and isoindigo for organic solar cells

作     者：Jialing Zhou Bao Zhang Yanfang Geng Qing Guo Qiang Guo Erjun Zhou 

作者机构：CAS Key Laboratory of Nanosystem and Hierarchical FabricationCAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190PR China Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing 100049PR China Henan Institute of Advanced TechnologyZhengzhou UniversityZhengzhou 450001PR China 

出 版 物：《Materials Reports(Energy)》 (材料导报（能源）（英文）)

年 卷 期：2021年第1卷第4期

页      面：68-76页

核心收录：

学科分类：0401[教育学-教育学] 04[教育学] 0807[工学-动力工程及工程热物理] 

基　　金：the National Key Research and Development Program of China(2017YFA0206600) the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH033) the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB36000000) the National Natural Science Foundation of China(NSFC,Nos.21875052,51873044,52073067) 

主　　题：Isoindigo Polymer donor materials D-π-A polymer Chlorination strategy Non-fullerene acceptor Voltage loss 

摘      要：Isoindigo(IID)has been widely used as strong acceptor unit(A)to construct narrow bandgap polymers in organic field effect transistors(OFETs)and organic solar cells(OSCs).Combing with IID,we chose benzodithiophene(BDT)as the donor unit(D)and thieno[3,2-b]thiophene(TT)as theπbridge to construct a new type of D-π-A polymer *** on PE70,we adopt the chlorination strategy to fine-tune photoelectric characteristics and film morphology,and then developed PE74 and *** blending with non-fullerene acceptor(NFA)Y6,device based on PE74 with chloride substitution on the BDT unit showed increasing photovoltaic *** addition,further chlorine substitution on the IID(PE75)would greatly reduce the non-radiative voltage loss(ΔV3),and the distorted molecular conformation also took responsible for the excessive *** results,PE74:Y6-based device achieves a power conversion efficiency(PCE)of 11.06%with open-circuit voltage(VOC)of 0.76 V,which are higher than those of PE70:Y6(PCE of 10.40%and VOC of 0.72 V)and PE75:Y6-based device(PCE of 6.24%and VOC of 0.84 V).This work demonstrates the regularity of the photovoltaic performance caused by chlorination strategy in polymer in the non-fullerene OSC devices,which provide important insights into highperformance photovoltaic materials.