Acceptor manipulation of bisalkylthiothienyl benzo[1, 2-b:4, 5-b']dithiophene core-structured oligomers for efficient organic photovoltaics. (May 2017)

• Record Type: Journal Article
• Authors: Yin, Xinxing; An, Qiaoshi; Yu, Jiangsheng; Xu, Zhongsheng; Deng, Ping; Geng, Yongliang; Zhou, Baojing; Zhang, Fujun; Tang, Weihua
• Is Part Of: Dyes and pigments. Volume 140(2017)
• Page Start: 512
• Page End: 519
• Publication Date: 2017-05
• Subjects: Organic solar cells -- Molecular donor -- Sidechain engineering -- Benzo[1, 2-b:4, 5-b']dithiophene -- Bisalkylthio; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2016.10.040
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: Three novel small molecules namedDR3TDST, DRCN3TDST andDB3TDST containing bisalkylthiothienyl side-chain on benzo[1, 2- b :4, 5 -b' ]dithiophene (BDT) core with different electron-deficient ending-groups are designed and synthesized. All three molecules have deep HOMO energy level from −5.40 eV to −5.44 eV, indicating introduction of bisalkylthio group to BDT is an effective method to modulate the molecular energy levels. Different ending-groups exhibit small but measurable effects on absorption, energy level, charge transport, morphology, and photovoltaic properties of small molecules. Bulk heterojunction solar cells fabricated withDRCN3TDST and PC71 BM deliverer the highest power conversion efficiency (PCE) of 5.17% after annealing and solvent vapor annealing. Graphic Abstract: Benzo[1, 2- b :4, 5 -b' ]dithiophene (BDT) core-structured small molecules with bisalkylthio side-group lowered HOMO levels showed the highest power conversion efficiency (PCE) of 5.17% in OSCs. Highlights: The synthesis of bisalkylthiobenzo[1, 2- b :4, 5- b' ]dithiophene based oligomers. The electrochemical characterization and molecular simulation of oligomers. The effect of ending acceptor on bisalkylthio BDT oligomer properties. The highest PCE of 5.17% for oligomer based OPVs.