Chen, H.-C.H.-C.ChenChen, Y.-H.Y.-H.ChenLiu, C.-H.C.-H.LiuHsu, Y.-H.Y.-H.HsuChien, Y.-C.Y.-C.ChienChuang, W.-T.W.-T.ChuangCheng, C.-Y.C.-Y.ChengLiu, C.-L.C.-L.LiuChou, S.-W.S.-W.ChouTung, S.-H.S.-H.TungChou, P.-T.P.-T.ChouSHIH-HUANG TUNGPI-TAI CHOU2018-09-102018-09-102013http://www.scopus.com/inward/record.url?eid=2-s2.0-84877695482&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/377465A tailor-made donor-π-acceptor copolymer comprising of a medium electron-donating alkylthienyl-benzodithiophene (BDTT) moiety and a strong electron-accepting fluorinated thienyl-quinoxaline (TTFQ) segment with thiophene π-bridge units has been synthesized by Stille coupling polymerization and thoroughly characterized for use as a p-type semiconducting polymer. The semicrystalline copolymer PBDTT-TTFQ shows a broad visible-near-infrared absorption band with an optical bandgap of 1.67 eV and possesses a relatively low-lying HOMO level at -5.34 eV. In addition, the PBDTT-TTFQ neat film reveals a highly dense fibrillar nanostructure with a certain degree of long-range order, suggesting the nanoscale self-assembly of PBDTT and TTFQ segments. A bulk-heterojunction polymer solar cell based on the blend of 1 : 1 PBDTT-TTFQ:PC71BM shows an open circuit voltage of 0.75 V, a short circuit current density of 14.6 mA cm-2, and a fill factor of 56.1%, achieving a power conversion efficiency of 6.1% under the illumination of AM 1.5G, 100 mW cm-2. The results unambiguously indicate that the PBDTT-TTFQ is an auspicious candidate for next-generation solar cell materials. © 2013 The Royal Society of Chemistry.[SDGs]SDG7Copolymers; Heterojunctions; Light absorption; Open circuit voltage; Solar cells; Thiophene; Bulk heterojunction; Electron-accepting; Electron-donating; Low-lying HOMO levels; Photovoltaic property; Polymer Solar Cells; Power conversion efficiencies; Solar cell materials; Polymersjournal article10.1039/c3py00235g2-s2.0-84877695482