Facile synthesized benzo[1,2-b:4,5-b']difuran based copolymer for both fullerene and non-fullerene organic solar cells

• Published in: Polymer (Guilford) Vol. 172; pp. 391 - 397
• Main Authors: Lei, Tao, Song, Wei, Fanady, Billy, Yan, Tingting, Wu, Lirong, Zhang, Wenxia, Xie, Lingchao, Hong, Ling, Ge, Ziyi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 20.05.2019; Elsevier BV
• Subjects: Benzodifuran; Circuits; Energy conversion efficiency; Energy levels; Fullerenes; Molecular orbitals; Organic chemistry; Organic solar cells; Photovoltaic cells; Polymer donor; Polymers; Short circuit currents; Short-circuit current; Solar cells; Substitutes; Organic solar cells; Benzodifuran; Polymer donor
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2019.04.014

A novel D-A conjugated polymer, PFBT-T, consisting of alkyl substituted benzo[1,2-b:4,5-b']difuran (BDF) as electron donor, alkyl substituted benzo[1,2-c:4,5-c']dithiophene-4,8-dione (BDD) as electron acceptor and thiophene as the π-bridge has been designed and synthesized through facile Stille coupling reaction. Compared with its reported similar polymer based on benzo[1,2-b:4,5-b']thiophene (BDT) unit, PFBT-T has deeper LUMO and HOMO energy level and more intense absorption in 350–550 nm, leading to higher short-circuit current density (Jsc) and open circuit voltages (Voc). Organic solar cells (OSCs) based on PFBT-T with architecture of ITO/PEDOT:PSS/PFBT-T:(PC71BM or IT-M)/PDINO/Al were fabricated. OSCs using PC71BM or IT-M as acceptors respectively obtained the power conversion efficiencies (PCEs) of 5.83% and 5.64%, which both were better than OSCs based on its BDT-based analogues. These results demonstrated that BDF was a promising donor constructing block which may replace BDT unit in some cases. New benzodifuran -based polymer PFBT-T was designed and synthesized, which was applied in both fullerene and non-fullerene organic solar cells. By blending polymer with IT-M, The optimal device performance exhibited a PCE of 5.64%, while in fullerene OSCs, optimal device performance exhibited a PCE of 5.83%. [Display omitted] •A facile way to synthesize benzo[1,2-b:4,5-b']difuran based copolymer with high yield.•Systematic investigation of PFBT-T by CV, TGA, DSC, UV–vis spectra and so on.•Synthesize benzo[1,2-b:4,5-b']difuran based copolymer achieved over 5.5% efficiency for both fullerene and non-fullerene solar cells.