Efficient polymer solar cells based on a copolymer of meta-alkoxy-phenyl-substituted benzodithiophene and thieno[3, 4-b]thiophene. Issue 26 (17th June 2016)

• Record Type: Journal Article
• Authors: Li, Wanbin; Guo, Bing; Chang, Chunmei; Guo, Xia; Zhang, Maojie; Li, Yongfang
• Is Part Of: Journal of materials chemistry. Volume 4:Issue 26(2016)
• Page Start: 10135
• Page End: 10141
• Publication Date: 2016-06-17
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6ta04030f
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A new conjugated polymerPBTF-OP was synthesized and the PSCs based onPBTF-OP :PC71 BM showed a PCE of 9.0%. Abstract : A new conjugated copolymer, PBTF-OP, based on meta -alkoxy-phenyl-substituted benzodithiophene (BDT- m -OP) and 2-ethylhexyl-3-fluorothieno[3, 4- b ]thiophene-2-carboxylate (TT) was designed and synthesized for application as the donor material in polymer solar cells (PSCs).PBTF-OP possesses a similar molecular structure to the well-known polymerPTB7-Th but different conjugated side chains on the BDT unit: meta -alkoxy-phenyl side chains forPBTF-OP and alkylthienyl side chains forPTB7-Th . Compared withPTB7-Th, PBTF-OP exhibits absorption with some blue shifts, while it possesses a deeper HOMO energy level of −5.45 eV and a slightly enhanced hole mobility of 1.25 × 10 −3 cm 2 (V −1 s −1 ) versus a HOMO energy level of −5.30 eV and a hole mobility of 1.11 × 10 −3 cm 2 (V −1 s −1 ) forPTB7-Th . The PSCs based onPBTF-OP :PC71 BM showed a higher power conversion efficiency (PCE) of 9.0% with a higher V oc of 0.86 V in comparison with a PCE of 8.3% and a V oc of 0.78 V forPTB7-Th . The results indicate that side chain engineering of BDT-based copolymers is an effective way to improve photovoltaic performance of polymer donors.