3,4‐Dicyanothiophene—a Versatile Building Block for Efficient Nonfullerene Polymer Solar Cells
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 07, 2020
- Source ID
- 10.1002/aenm.201904247
Entities
People
- Bo Zhang
- Chunhui Duan
- Fei Huang
- Haoran Tang
- Harald Ade
- Hin‐lap Yip
- Jiadong Zhou
- Liuyong Hu
- Long Ye
- Shenkun Xie
- Yong Cao
- Yonggao Yu
- Zengqi Xie
- Zhenfeng Wang
- Zhicai He
- Zhitian Liu
Organizations
- Ministry of Science and Technology of the People's Republic of China
- National Natural Science Foundation of China
- North Carolina State University
- Office of Naval Research
- South China University of Technology
- Tianjin University
- United States Department of Energy
- Wuhan Institute of Technology