3,4‐Dicyanothiophene—a Versatile Building Block for Efficient Nonfullerene Polymer Solar Cells

Journal Article · 07 February 2020 · Advanced Energy Materials

DOI: https://doi.org/10.1002/aenm.201904247 · OSTI ID:1598374

Zhang, Bo ^[1]; Yu, Yonggao ^[2]; Zhou, Jiadong ^[2]; Wang, Zhenfeng ^[2]; Tang, Haoran ^[2]; Xie, Shenkun ^[2]; Xie, Zengqi ^[2]; Hu, Liuyong ^[3]; Yip, Hin‐Lap ^[2]; Ye, Long ^[4]; Ade, Harald ^[5]; Liu, Zhitian ^[3]; He, Zhicai ^[2]; Duan, Chunhui  ^[2]; Huang, Fei ^[2]; Cao, Yong ^[2]

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1. Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 P. R. China, Institute of Materials for Optoelectronics and New Energy School of Materials Science and Engineering Wuhan Institute of Technology Wuhan 430205 P. R. China
2. Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 P. R. China
3. Institute of Materials for Optoelectronics and New Energy School of Materials Science and Engineering Wuhan Institute of Technology Wuhan 430205 P. R. China
4. Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 P. R. China, School of Materials Science &, Engineering Tianjin University Tianjin 300350 P. R. China, Department of Physics and ORaCEL North Carolina State University Raleigh NC 27695 USA
5. Department of Physics and ORaCEL North Carolina State University Raleigh NC 27695 USA

Abstract In this contribution, a versatile building block, 3,4‐dicyanothiophene (DCT), which possesses structural simplicity and synthetic accessibility for constructing high‐performance, low‐cost, wide‐bandgap conjugated polymers for use as donors in polymer solar cells (PSCs), is reported. A prototype polymer, PB3TCN‐C66, and its cyano‐free analogue polymer PB3T‐C66, are synthesized to evaluate the potential of using DCT in nonfullerene PSCs. A stronger aggregation property in solution, higher thermal transition temperatures with higher enthalpies, a larger dipole moment, higher relative dielectric constant, and more linear conformation are exhibited by PB3TCN‐C66. Solar cells employing IT‐4F as the electron acceptor offer power conversion efficiencies (PCEs) of 11.2% and 2.3% for PB3TCN‐C66 and PB3T‐C66, respectively. Morphological characterizations reveal that the PB3TCN‐C66:IT‐4F blend exhibits better π–π paracrystallinity, a contracted domain size, and higher phase purity, consistent with its higher molecular interaction parameter, derived from thermodynamic calculations. Moreover, PB3TCN‐C66 offers a higher open‐circuit voltage and reduced energy loss than most state‐of‐the‐art wide‐bandgap polymers, without the need of additional electron‐withdrawing substituents. Two additional polymers derived from DCT also demonstrate promising performance with a higher PCE of 13.4% being achieved. Thus, DCT represents a versatile and promising building block for constructing high‐performance, low‐cost, conjugated polymers for application in PSCs.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1598374
• Journal Information: Advanced Energy Materials, Journal Name: Advanced Energy Materials Journal Issue: 12 Vol. 10; ISSN 1614-6832
• Publisher: Wiley Blackwell (John Wiley & Sons)Copyright Statement
• Country of Publication: Germany
• Language: English