| 초록 |
Two donor−acceptor (D−A) low band gap polymers, P1 and P2, Fluorenylthiophene Linked Benzodithiophene (FlT-BDT) linked benzodithiophene (BDT) with different alkyl chains as an electron-rich unit and 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP) as an electron-deficient unit, have successfully been synthesized via microwave-assisted Stille polymerization and utilized for bulk heterojunction (BHJ) polymer solar cells (PSCs). The resulting copolymers exhibit broad and strong absorption bands from 350 to 1000 nm with low optical band gaps below 1.40 eV. As these polymers possess good thermal properties, film forming nature and very low bandgap, they appear to be interesting candidates for organic solar cell applications. The introduction of fluorenylthiophene as a highly conjugation extendable side chain is attractive because of its ability to reduce the bandgap for more light harvesting for superior photovoltaic properties. |
