Alkylthio-substitution on wide bandgap conjugated polymers for non-fullerene acceptor-based organic solar cells. (November 2020)

• Record Type: Journal Article
• Authors: Park, Kiyoung; Sun, Cheng; Jang, Soo-Young; Wang, Canjie; Li, Jiaqiang; Zhao, Quinghua; Kang, Hongkyu; Lee, Kwanghee; Kwon, Soon-Ki; Kim, Yun-Hi
• Is Part Of: Dyes and pigments. Volume 182(2020)
• Publication Date: 2020-11
• Subjects: Organic photovoltaic cells -- Conjugated polymer -- Wide bandgap -- Alkythio groups -- HOMO energy level; BDD benzo[1, 2-c:4, 5-c']dithiophene-4, 8-dione -- BDT benzo[1, 2-b:4, 5-b']dithiophene -- DIO 1, 8-diiodooctane -- ITIC 3, 9-bis(2-methylene-(3-(1, 1-dicyanomethylene)-indanone))-5, 5, 11, 11-tetrakis(4-hexylphenyl)-dithieno[2, 3-d:2′, 3′-d']-s-indaceno[1, 2-b:5, 6-b']dithiophene -- NFA Non-fullerene acceptors -- IT-M 3, 9-bis(2-methylene-((3-(1, 1-dicyanomethylene)-6/7-methyl)-indanone))-5, 5, 11, 11-tetrakis(4-hexylphenyl)-dithieno[2, 3-d:2′, 3′-d']-s-indaceno[1, 2-b:5, 6-b']dithiophene; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2020.108601
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: We investigated three conjugated polymers, PSBDB-T, P1SBDB-TS, and PSBDB-TS, having different numbers of alkylthio groups. The polymers showed a wide bandgap of 1.76–1.81 eV with broad absorption range from 300–700 nm and were used as donor polymers in organic photovoltaic (OPV) devices with the non-fullerene acceptor, IT-M. By increasing the number of alkythio groups in their chemical structures, the HOMO levels of the polymers down-shifted as −5.46 eV, −5.51 eV and −5.56 eV, and consequently, the V OC of the OPV cells gradually increased as 0.91 V, 0.92 V and 0.94 V for PSBDB-T, P1SBDB-TS, and PSBDB-TS, respectively. P1SBDB-TS having three alkylthio groups (two for benzo[1, 2- b :4, 5- b ']dithiophene and one for benzo[1, 2- c :4, 5- c ']dithiophene-4, 8-dione unit) showed the best power conversion efficiency of 6.88% among three polymers due to its high crystallinity and low bimolecular recombination in bulk heterojunction system. Graphical abstract: Image 1 Highlights: Wide bandgap donor polymers for organic photovoltaics developed. Influence of alkylthio groups on photovoltaic donor polymers investigated. The polymer with three alkylthio groups overall gave the best power conversion efficiency of 6.88%.