Putri SK, Kim YH, Whang DR, Kim JH, Chang DW. Synthesis of Trifluoromethylated Quinoxaline-Based Polymers for Photovoltaic Applications.
Macromol Rapid Commun 2018;
39:e1800260. [PMID:
29974539 DOI:
10.1002/marc.201800260]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/16/2018] [Indexed: 11/09/2022]
Abstract
A series of quinoxaline-based conjugated polymers, in which the electron-donating benzodithiophene (BDT) unit is linked to the electron-accepting 6,7-difluorinated quinoxaline (DFQ) derivatives by a thiophene bridge, is synthesized. To investigate their effects on the intrinsic properties of polymers, strong electron-withdrawing trifluoromethyl (CF3 ) groups were incorporated into the meta-position of the phenyl ring at the 2,3-positions of the DFQ unit of the reference polymer, labelled PEhB-FQx, to yield the target polymer PEhB-FQxCF3. In addition, the 2-ethylhexyloxy substituents on the BDT donor in PEhB-FQxCF3 are changed to the more planar 2-ethylhexyl thiophene units to produce another target polymer PThB-FQxCF3. Owing to the significant contributions of the CF3 moiety, PEhB-FQxCF3 exhibits quite discernible optical and electrochemical properties along with significant enhancement in photovoltaic performances compared to the reference polymer PEhB-FQx. Furthermore, the incorporation of the alkylthienyl side chains on the BDT moiety confers on the resultant PThB-FQxCF3 to possess the maximum power conversion efficiency of 7.26% with an open circuit voltage of 0.88 V, short-circuit current density of 12.20 mA cm-2 , and fill factor of 67.80%.
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