Enhanced Photovoltaic Performance of Low-Bandgap Polymers with Deep LUMO Levels


  • The authors would like to thank the University of North Carolina at Chapel Hill and the ONR (Grant No. N000140911016) for financial support, and are grateful for a DuPont Young Professor Award and a NSF CAREER Award (DMR-0954280). We also thank Prof. Richard Jordan and Zhongliang Shen of the University of Chicago for GPC characterization. LUMO=lowest unoccupied molecular orbital.


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Mind the gap! Polymers synthesized by replacing the benzene unit in the acceptor 4,7-dithien-2-yl-2,1,3-benzothiadiazole (DTBT) with a π-electron-deficient pyridine unit (DTPyT) show a smaller bandgap than their DTBT counterparts. Power conversion efficiencies of over 6 % are demonstrated in solar cell studies (see picture; PNDT, PQDT, and PBnDT represent dithiophene derivatives as weak donors).