Fluorinated thienyl-quinoxaline-based D-π-A-type copolymer toward efficient polymer solar cells: Synthesis, characterization, and photovoltaic properties
Journal
Polymer Chemistry
Journal Volume
4
Journal Issue
11
Pages
3411-3418
Date Issued
2013
Author(s)
Chen, H.-C.
Chen, Y.-H.
Liu, C.-H.
Hsu, Y.-H.
Chien, Y.-C.
Chuang, W.-T.
Cheng, C.-Y.
Liu, C.-L.
Chou, S.-W.
Tung, S.-H.
Chou, P.-T.
Abstract
A 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
Other Subjects
Copolymers; 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; Polymers
Type
journal article