The development of new materials plays a critical role in improving the efficiency of organic solar cells(OSCs).At present,the relatively high-lying highest occupied molecular orbital(HOMO)level of the high-efficiency polymer donor is regarded as one of the main reasons for the low open-circuit voltage(Voc).In this work,we introduced the strong electron-withdrawing thiazole unit into the construction of a polymer donor.We designed and prepared an alternating donor-acceptor material,namely PSZ,by copolymerizing 4-methyl thiazole with an electron-donating benzodithiophene unit and studied its application in high-efficiency OSCs.The optical and electrical properties of the new material were characterized by UV-Vis absorp-tion spectroscopy and electrochemical cyclic voltammetry.Results show that PSZ is a typical wide-bandgap material with a high optical bandgap of 2.0 eV and a deep HOMO level of-5.70 eV.When a non-fullerene BTP-eC9 was selected as the acceptor material,Voc reached 0.88 V in the resulting device,and the corresponding power conversion efficiency(PCE)was 8.15％.In addition,when PSZ was added as the third component to the binary photoactive combination with PBDB-TF as the donor and BTP-eC9 as the acceptor,Voc of the cell device could be increased,thereby obtaining a high PCE of 17.4％.These results indicated that introducing thiazole units into polymer donors can remarkably reduce the HOMO levels and improve Voc and PCE in OSCs.

Ye Xu;Huifeng Yao;Tao Zhang;Lijiao Ma;Jianhui Hou

State Key Laboratory of Polymer Physics and Chemistry,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China

天津大学学报（英文版）

[1]Ye Xu;Huifeng Yao;Tao Zhang;Lijiao Ma;Jianhui Hou-.A Thiazole-Based Polymer Donor for Efficient Organic Solar Cells)[J].天津大学学报（英文版）,2022(05):398-405

Thiazole

Based,Polymer,Donor,Efficient,Organic,Solar,Cells,development,new,materials,plays,critical,role,improving,efficiency,organic,solar,cells,OSCs,At,present,relatively,lying,highest,occupied,molecular,orbital,HOMO,regarded,main,reasons,low,open,circuit,voltage,Voc,In,this,work,introduced,strong,electron,withdrawing,thiazole,into,construction,We,designed,prepared,alternating,acceptor,namely,PSZ,copolymerizing,methyl,donating,benzodithiophene,studied,application,optical,electrical,properties,were,characterized,UV,Vis,absorp,spectroscopy,electrochemical,cyclic,voltammetry,Results,show,that,typical,wide,bandgap,eV,deep,When,fullerene,BTP,eC9,was,selected,reached,resulting,device,corresponding,power,conversion,PCE,addition,when,added,third,component,binary,photoactive,combination,PBDB,TF,could,increased,thereby,obtaining,These,results,indicated,introducing,units,donors,can,remarkably,reduce,levels,improve

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